JP2010023051A - Light metal member produced from melt and its manufacturing method - Google Patents

Abstract

Kind Code: A1 A second type Al alloy material excellent in wear resistance that can be produced at low cost is provided.
A method for producing a melted light metal member according to the present invention comprises supplying a light metal melt (M) such as an Al alloy to a roll casting machine (1), and rotating the mold metal (11, 12) to rotate the light metal melt. A material casting process in which a continuous plate material (R) is cast while rapidly solidifying and rapidly solidifying the material, and plastic processing is applied to at least the plate material in a warm state by the residual heat during the material casting process to create a desired shape. And a shape creation step for forming a base material. The plate-like material after the material casting process has a fine structure by rapid solidification and is plastically processed in the shape creation process at least in a warm state by residual heat during casting. For this reason, according to the manufacturing method of the present invention, efficient and high-quality molding can be performed without bothering reheating, and both energy saving and improvement in yield and production efficiency can be achieved.
[Selection] Figure 1

Description

  The present invention relates to a melted light metal member obtained by molding a plate-like material obtained by melting and a method for manufacturing the same.

  In order to reduce the weight of members, devices, and vehicles, conventional iron-based members are being replaced by Al-based or Mg-based light metal members. This tendency extends not only to cases and housings but also to functional members that require wear resistance and slidability. For example, in the case of automobile members, the cylinder liner of an internal combustion engine (reciprocating engine) is being replaced by Al alloy from conventional graphite cast iron.

  However, even if such an alternative is made, functions (strength, wear resistance, etc.) equal to or higher than those of conventional ones must be ensured. The proposal regarding this is described in the following patent document 1 and patent document 2.

  First, Patent Document 1 proposes a cylinder liner using a sintered Al alloy member obtained by forming and sintering a powder Al alloy in which graphite particles and hard particles are dispersed. In Patent Document 2, it is proposed to spray the Al-high Si alloy powder on the cylinder liner surface.

  However, in any of these cases, it is necessary to further mold, sinter, or spray the high-cost Al alloy powder. Therefore, in such an Al alloy member using powder, even if the required function is ensured, it is difficult to easily reduce the manufacturing cost. On the other hand, in gravity casting, die casting, etc. with good productivity, it is difficult to obtain an Al alloy member that sufficiently satisfies the required characteristics, no matter how much the chemical composition is adjusted.

Patent Documents 3 to 5 propose that a general-purpose Al alloy material manufactured by continuous casting and rolling is used for a light metal member in order to reduce manufacturing costs and energy consumption. However, in such a light metal member, although the properties as a single material are good, the formability to the member is inferior and the processing cost is high, so that the production cost cannot be effectively reduced after all.
Japanese Patent No. 3234810 JP 2003-286501 A JP-A-8-165538 JP 2004-156117 A JP 2006-249550 A

  This invention is made in view of such a situation, and provides the manufacturing method of the melted light metal member which can manufacture the shape material of the desired shape which consists of light metals at low cost and low energy consumption. Objective. Moreover, it aims at providing the melted light metal member excellent in each characteristic manufactured by the method.

  As a result of intensive research to solve this problem and repeated trial and error, the present inventor added plastic working to the plate-like material obtained by rapidly solidifying a light metal melt and rapidly forming it into a desired shape. I came up with the idea of creating a shape on the material, and succeeded in obtaining a melted light metal member with excellent properties at low cost. By developing this result, the present inventor has completed various inventions described below.

<Method for producing melted light metal member>
(1) That is, in the method for producing a melted light metal member of the present invention, an aluminum (Al), an Al alloy, a roll casting machine having an annular mold part on the outer peripheral surface side and having at least one rotating cooling roll, A material casting step of supplying a molten metal made of a light metal that is either magnesium (Mg) or an Mg alloy, and casting a continuous plate-shaped material while rapidly solidifying the molten light metal in the mold part; and
And a shape creation step of forming a shaped material that is created into a desired shape by applying plastic working to at least a plate-like material in a warm state due to residual heat during the material casting step.

(2) According to the method for producing a melted light metal member of the present invention, a material casting process for continuously casting a plate material, and a plate material obtained in the material casting process is subjected to plastic working to create a desired shape. A shape creation process for forming a silicon shape material is performed in a short time.
For this reason, in the shape creation process of plastically deforming the plate-shaped material, it is not necessary to reheat the plate-shaped material, and the remaining heat of the material casting process can be used in the shape creation process. Therefore, while saving energy, the plate-like material can be plastically processed in the warm state or in the hot state, and can be molded without causing cracks, etc., and a desired shape can be obtained quickly and at low cost. Can do.
Moreover, since the plate-like material according to the present invention is obtained by rapid solidification by a casting method (roll casting method) using a cooling roll, the metal structure is very fine. For this reason, the shaped material obtained by creating a shape of a plate-shaped material is excellent in various properties (for example, strength, ductility, toughness, heat resistance, wear resistance, etc.) according to the chemical composition of the light metal.

Furthermore, not only such mechanical characteristics, but also the fact that the plate-shaped material is rapidly solidified contributes greatly to the formability in the subsequent shape creation process. In other words, as a result of intensive research conducted by the present inventors, the plate-like material is rapidly solidified so that even if the plate-like material is subjected to strong processing, the plate-like material is cracked. Therefore, a shape creation process with good yield is performed.
Thus, according to the manufacturing method of the melted light metal member of the present invention, the material casting process and the shape creation process act synergistically, and not only energy saving but also improvement of formability of the plate-shaped material and shape material The production cost is reduced by improving the yield, and the obtained shaped material is also excellent in each characteristic.

<Melted light metal parts>
The present invention can be grasped not only as a method for producing a melted light metal member, but also as a melted light metal member obtained thereby.

<Others>
(1) Unless otherwise specified, “x to y” in this specification includes a lower limit x and an upper limit y. Moreover, the upper and lower limit values described in the present specification can be arbitrarily combined to constitute a range such as “ab”.
The “inevitable impurities” as used in the present invention are impurities contained in raw materials, impurities mixed during casting, molding, etc., and are elements that are difficult to remove due to cost or technical reasons. .

The “modifying element” is an element other than the essential elements of the present invention (Al, Mg, Si or Cu or Fe, Ti, Zr, Nb, Hf, Sc or Y), and improves the characteristics of the melted light metal member. Is an effective element. There is no limitation on the type of characteristics to be improved, and the combination of these elements is arbitrary.
In addition, since the composition of the above elements is important, the composition of the modifying element is not particularly limited, but for example, P: 0.001 to 0.1%, B: 0.01 to 0.3%, Cr: 0.01-0.3%, V: 0.01-0.3%, Mn: 0.01-0.3%.

(2) “Melting” as used in the melted light metal member of the present invention not only indicates a simple manufacturing method but also indirectly specifies the form of the metal structure or the like by using the expression of the manufacturing method for convenience. Yes. As a result, the molten light metal member of the present invention is distinguished from at least a conventional casting material such as die casting or gravity casting, forging material, sintered material, thermal spraying material, or the like.

(3) It is not easy to specify “quick solidification” in the present invention. If it is intended to specify rapid solidification, when the cooling rate is higher than that of die casting, more specifically, the lower limit of the cooling rate is 100 ° C / second, 150 ° C / second, 200 ° C / second. Furthermore, it is 250 ° C./second. Although it is not necessary to specify an upper limit, if it dares from a realistic viewpoint, it will be about 10000 degrees C / sec.

  In addition, the presence or absence of rapid solidification can be indirectly determined from the metal structure of a plate-like material or a shaped material determined according to the chemical composition of the light metal. For example, assuming that it is within a specific chemical composition range, the average particle size of primary crystals (for example, the average particle size of primary crystal Si particles), the size of DAS, the average particle size of crystals and precipitates, It is considered that the presence / absence and range of rapid solidification can be indirectly specified by the amount of dispersion.

(4) The “plate shape” of the plate-like material referred to in the present invention is usually a case where the width (W) is larger than the thickness (T) (T <W), but is not limited thereto, and is a so-called bar shape. , Rod-shaped, tubular, groove-shaped, etc. In short, the plate-shaped material of the present invention does not have a problem with its specific shape and size as long as it can be plastically processed to form a light metal member or a shape material close thereto.

  Their cross-sectional shapes are not limited to regular shapes such as squares (triangles, quadrilaterals, pentagons, hexagons, octagons, etc.) and round shapes (circulars, ellipses, etc.), but also C shapes, L shapes, channel shapes, etc. Different shapes may be used. This irregular shape includes an uneven thickness (uneven thickness material) having an unevenly thick portion. Such uneven thickness portions are, for example, one side in the width direction, both sides, substantially the center side, one side or both sides in the thickness direction.

  However, if the upper limit of the thickness of the plate material is 8 mm or 6 mm and the lower limit is 0.5 mm or 1 mm, the plate material is solidified at a large cooling rate and exhibits good moldability. In addition, the base material or light metal member made of the plate-like material has sufficient strength and rigidity as a part. In addition, it is preferable that the width | variety of a plate-shaped raw material is 2500 mm or less at the point from which a homogeneous structure | tissue is obtained in the width direction.

(5) The “material” of the plate-like material referred to in the present invention may be a so-called roll cast casting, or may be a material obtained by adding some rolling or the like. In other words, the “material” of the plate-shaped material means “material” that is used in the shape creation process after the material casting process, and has undergone some processing unless the form after roll casting is significantly changed. Is also included in the “plate material” in the present invention.

(6) On the other hand, the “original material” referred to in the present invention does not include a material obtained by simply adjusting the thickness and metal structure of the cast material after roll casting by rolling or the like. A shaped material is obtained by applying plastic working to a plate-like material to bring it close to the shape of the final light metal member. For example, a plate-shaped material is a so-called near net shape or net shape. From the viewpoint of “plastic processing” in the shape creation process, processing such as simply rolling a sheet material does not correspond to plastic processing in the present invention, and “plastic processing” in the shape creation process. "It can be said that the plate-shaped material is formed into a desired shape close to the final shape of the light metal member.

(7) The “warm state” in the shape creation process refers to a state of heating to a temperature exceeding normal temperature and lower than the recrystallization temperature. Incidentally, the “hot state” refers to a state of being heated to the recrystallization temperature or higher and lower than the melting point.
Since these differ depending on the chemical composition of the light metal and the degree of plastic working, it is difficult to specify their specific temperature range. If it dares, the warm state in the plate-shaped raw material made of Al alloy is, for example, 150 to 300 ° C. or 200 to 280 ° C. Moreover, the hot state in the plate-shaped material made of Al alloy is, for example, 350 to 500 ° C., further 400 to 480 ° C.

The present invention will be described in more detail with reference to embodiments of the invention. In addition, the content demonstrated by this specification including the following embodiment is applicable not only to the melted light metal member which concerns on this invention but its manufacturing method suitably. Which embodiment is the best depends on the target, required performance, and the like.
And in addition to the structure mentioned above, this invention which concerns on a molten light metal member or its manufacturing method can further add one or two or more arbitrarily selected from the structure enumerated next. At that time, it is possible to add a configuration extracted in a superimposed manner or arbitrarily beyond the category. For example, if it is the structure regarding the composition of a melted light metal member, it cannot be overemphasized that it is related also to the thing itself and its manufacturing method. Even if it looks like a configuration related to “method”, it can be a configuration related to “thing” if it is understood as a product-by-process.

"Production method"
<Material casting process (roll cast)>
(1) The material casting process is a process of manufacturing a plate-shaped material by supplying light metal solution, which is one of Al, Al alloy, Mg or Mg alloy, to a roll casting machine and rapidly solidifying it with a cooling roll of the roll casting machine. is there. The roll casting machine referred to in the present invention only needs to have at least one cooling roll.
For this reason, the roll casting machine may be, for example, a casting machine in which a cooling roll and a cooling belt, a cooling roll and a pressure (forming) roll, or a cooling roll and a cooling roll (double roll) are combined.
Conventionally, a roll casting machine has been used for continuous casting of steel sheets and the like. However, in the present invention, not only for producing simple plate materials, but for efficiently producing molten light metal members having more complicated shapes. A roll casting machine is used as one process.
The roll casting machine is preferably a twin roll casting machine in which at least a pair of cooling rolls are arranged opposite to each other in order to stably rapidly cool and solidify the molten metal and efficiently produce a high-quality plate material. . Hereinafter, for convenience, this twin roll casting machine will be mainly described.

  In a twin roll casting machine, usually, a pair of cooling rolls (referred to as “twist rolls” as appropriate) opposed to each other by an annular mold part provided on the outer peripheral surface side and a molten metal supplied to the twin rolls are temporarily provided. A molten metal reservoir that can adjust the supply amount to the twin rolls, an adjustment mechanism that adjusts the distance between the pair of cooling rolls, a driving device that drives each cooling roll, and a cooling device that cools the cooling roll. .

  The cross-sectional shape of the annular mold part of one cooling roll is determined according to the shape of the plate-shaped material used for the shape creation process. For example, if the plate-like material is a flat plate-like material having a substantially constant plate thickness, the mold part may be a flat annular band. In this case, it is sufficient to make the mold part of the other cooling roll facing the same shape. However, if the plate material is a flat material, the mold portion of each cooling roll may have a substantially U-shaped cross section (concave shape) in which the outer peripheral center portion is thinly carved. Moreover, it is good also considering only the casting mold part of one cooling roll of the opposing roll as a concave shape, and making the casting mold part of the other cooling roll into a flat annular belt.

Further, even if the mold part of at least one cooling roll is an annular groove having a concave cross-sectional shape in the width direction of the cooling roll, the cross-sectional shape in the width direction is uneven by changing the degree of depression in the width direction. An uneven plate-shaped material (uneven-walled material) can also be obtained.
As described above, when the plate material is continuously cast by the roll casting machine, the shape of the mold part of the cooling roll can be variously changed, and accordingly, the plate material of various shapes can be selected according to the shape of the melted light metal member. Can be obtained continuously. In that case, both mold parts of the opposed cooling rolls do not necessarily have a symmetrical shape, and various changes can be made within a range in which rapid solidification of the plate-like material and stable formability thereof can be ensured.

The diameter, width, etc. of the cooling roll are determined according to the desired size of the plate material, and the roll gap is also determined according to the desired thickness of the plate material. The cooling rolls may be arranged not only when the rotating shafts of the respective cooling rolls are arranged substantially horizontally, but also when the rotating shafts of the respective cooling rolls are arranged substantially vertically by devising the form and arrangement of the molten metal pool. . When horizontally arranged, it is easy to adjust the speed at which the molten metal is supplied from the molten metal pool to the cooling roll as much as the influence of gravity can be suppressed.
In addition, what is necessary is just to perform the replenishment of the molten metal to a molten metal pool suitably, adjusting a replenishment amount via a molten metal replenishment nozzle. The cooling roll drive device can drive each cooling roll with the set rotational direction and rotational speed. Usually, each cooling roll rotates synchronously.

  It is preferable that the cooling device for the cooling roll always cools the mold portion of the cooling roll by water cooling from the inner peripheral surface side of the cooling roll in order to rapidly cool and solidify the molten metal. In this water cooling, for example, a jet of cooling water can be applied to the inner peripheral surface of the cooling roll. As a result, large heat removal is possible, and the mold part can be cooled stably.

  However, not only the cooling roll cooling method but also the cooling roll mold itself has a large thermal conductivity in order to quickly remove heat from the molten metal coming into contact with the mold part of the cooling roll and rapidly cool and solidify the molten metal. It is also important to have Therefore, at least the vicinity of the outermost surface of the mold part of the cooling roll is made of a high heat conductive material, and the thermal conductivity is preferably 50 W / m · k or more, 100 W / m · k or more, further 200 W / m · k or more. An example of such a high thermal conductivity material is Cu or Cu alloy. For example, if it is made of pure Cu, its thermal conductivity is about 350 to 400 W / m · k. Incidentally, as this high thermal conductive material, various copper alloys such as 96% <Cu <99.3% high copper alloy, brass, bronze, Cu—Be based copper alloy can be used in addition to pure Cu. Other high heat conductive materials such as general steel materials such as carbon steel and chrome steel, and steel for die casting with improved thermal conductivity are also realistic. Although the temperature of the light metal melt varies depending on its chemical composition, it is at most about 850 ° C., so that a metal having a relatively low melting point can be used if the thermal conductivity is high.

(2) The casting of the plate material by the roll casting machine is performed as follows.
First, solidification starts from the point (solidification start point) at which the molten metal contacts the outer peripheral surface of the cooling roll. From this solidification start point to the point where the roll interval is minimized (roll kiss point), a cylindrical solidified shell formed by solidifying the light metal melt is formed on the outer peripheral surface of the cooling roll and grows. And the solidified shell formed on the surface of the opposing cooling roll is pressure-bonded at the roll kiss point to obtain a plate-shaped material having a predetermined thickness corresponding to the roll interval.

  Since the plate-like material obtained using such a roll casting machine is hot-rolled at the stage of exiting the roll casting machine, it has almost no defects without causing cracks.

(3) The operating conditions of the roll casting machine may be appropriately adjusted according to the desired shape and specifications of the Al alloy member. For example, it is preferable if the roll peripheral speed is about 1 to 60 m / min and the roll interval (plate thickness) is about 1 to 10 mm. When a copper cooling roll is operated under such conditions, the cooling rate of the plate-like material is 102 to 104 on the plate thickness average. It becomes about ° C / second. Of course, the actual cooling rate differs depending on the size of the cooling roll with respect to the plate-shaped material, the cooling method of the cooling roll, etc., and it is difficult to specify it in general.
(4) In the raw material casting process or after (or immediately after) the raw material casting process, a cooling process is provided in which the plate-shaped material that has been rapidly solidified by a cooling roll and separated from the cooling roll is cooled to a predetermined temperature by a cooling medium. It is preferable.
Thereby, even when the plate-shaped material has a large thickness, the plate-shaped material after exiting the roll casting machine can be surely rapidly cooled and solidified. Thereby, regardless of the plate thickness, a plate-like material that is stable in quality and has a fine solidified structure up to the inside can be obtained. Here, “cool to a predetermined temperature” means to keep the plate-like material at least in a warm state in preparation for the next shape creation process without completely cooling the plate-like material to room temperature or below. Means. The cooling medium is a cooling liquid such as water or oil, or a cooling gas such as an inert gas or air. Examples of the method of contacting the plate-like material with the cooling medium include immersion in a cooling bath, spraying in a shower form or mist form.

<Shape creation process>
(1) The shape creation step is a step of obtaining a shaped material created in a desired shape by molding (plastic working) a plate-like material following roll casting. Although this process is possible even in a cold state, in the present invention, warm processing or hot processing using preheating at the time of roll casting is performed. Thus, with conventional cold working, even if cracking or the like occurs, the shape creation process of the present invention can produce a light metal member such as an Al alloy member with high yield without causing cracking or the like. For example, even when a plate-like material with a large number of hard Si particles dispersed therein is hard-worked, it does not cause cracks, etc., and it can improve productivity with a high yield and has a desired shape with a relatively low molding load. Can be molded into For this reason, the facility capacity can be saved and the production cost of the melted light metal member can be reduced.

  As described above, it is not only the processing temperature of the plate-shaped material, but also the plate-shaped material that is rapidly solidified by solidification, and the metal structure is fine. It contributes greatly. Therefore, the high-quality light metal member can be efficiently produced by the present invention is largely due to the synergistic action of the material casting process and the shape creation process.

Incidentally, the temperature of the plate-like material after the material casting step is naturally a temperature below the solidus, but still about 100 to 500 ° C., preferably about 200 to 400 ° C. From the viewpoint of effectively utilizing the residual heat during the material casting process, the shape creation process is preferably performed as soon as possible after the material casting process. However, the longer the shape creation process after the material casting process, the lower the temperature of the plate-like material. Therefore, the plate-like material can be warmed or reheated by auxiliary heating or reheating during the shape creation process. You may provide the heating process which makes it an intermediate state.
Incidentally, although the case where warm processing or hot processing is performed is described, since the plate-like material according to the present invention has a fine structure as a whole, the present inventor has a considerably high cold formability. Has been confirmed.

(2) Plastic processing The type of plastic processing of the plate-shaped material that is performed in the shape creation step is not limited as long as a desired shape is imparted to the plate-shaped material to obtain a shaped material. Simple rolling or the like is merely an amount for changing the plate thickness or the like of the plate-shaped material, and is not included in the plastic working as used in the present invention because it is not a plastic working for forming a raw material.

Examples of the plastic working in the present invention include roll forming, pressing, punching, burring, hemming and the like. Any one or more of the plastic workings are sufficient, and a combination of a plurality of types may be used.
Here, “roll forming” refers to a processing method in which a frame structure or a pipe-like structure is formed by deforming a pair of male and female rolls by passing a long strip.

“Pressing” means placing a plate-shaped material between molds (press molds) having unevenness in a press machine, and applying a molding load between the molds to form the plate-shaped material in a desired shape. This refers to processing that causes plastic deformation (shearing, bending, drawing, etc.).
“Punching” is a process of punching a plate-shaped material into a desired shape by applying a die.
The “burring process” is a process in which a hole is formed at the same time as a hole is made in a plate material and a flange shape is formed around the hole.
The “hemming process (curling process)” is a process of bending the workpiece end.
In addition to such plastic processing, bending processing that folds or bends the plate material into a three-dimensional shape, spinning processing that creates a desired shape with a spatula or roller by applying a rotational motion to the plate material, plate Plastic processing such as embossing that creates a relatively shallow uneven shape such as a pattern or a character while suppressing a change in the plate thickness by using the elongation of the shaped material may be used. It is also possible to bend a frame-like structure (raw material) or pipe-like structure (raw material) made by roll forming.

By the way, since the material shape to be subjected to such plastic working is basically a plate shape, there is a corresponding limitation on the shape that can be created. However, as described above, the plate-like material referred to in the present invention is not only a flat plate material. In other words, by changing the shape of the mold part on the outer peripheral surface side of the cooling roll, it is possible to efficiently produce plate-shaped materials of various shapes, and therefore, shaped materials.
By forming such a deformed material (plate-shaped material) into a shaped material by plastic working, it is possible to actually manufacture various melted light metal members that are practically used according to the present invention. In addition, the shape such as the square shape, the bowl shape, or the uneven thickness shape may be provided as the shape of the plate material in the material casting process, but the shape material of the shape material in the shape creation process may be applied to the flat plate material. It may be given as a shape.

However, the melted light metal member as in the present invention is rarely required to have a complicated shape such as a die cast product or a gravity cast product. Therefore, hereinafter, a case where a flat plate-shaped material is formed into a simple cylindrical shape by roll forming will be described as a representative example.
In this case, the axis of the cylinder may be along the feed direction in which the plate-shaped material is sent out from the roll casting machine (longitudinal direction), or the cylinder axis may be perpendicular to the feed direction of the roll casting machine ( (Landscape). However, if a cylindrical Al alloy member is produced continuously and efficiently, it is preferable to form the cylindrical axis along the feed direction of the roll casting machine as in the former case.

The forming speed is not particularly limited, but a speed corresponding to or synchronized with the speed of the raw material casting process is preferable because a molten light metal member can be produced continuously and smoothly.
In particular, such a simple member having a cylindrical shape or a semicylindrical shape is often used as a wear-resistant member used for a portion that rotates or slides. Therefore, the manufacturing method of the present invention in which plastic forming is roll forming is suitable for manufacturing such a member.

<Additional process>
(1) Cutting process A plate-like material that is actually manufactured is a continuous material that is sequentially cast and conveyed. For this reason, even if it is not an essential process of the present invention, the shape creation process requires an appropriate location before the shape creation process as long as the shape creation process does not include a separation process for separating the respective raw materials or a cutting process for cutting the plate-like material. Or the process of cutting the plate-shaped raw material after a shape creation process is needed.
Therefore, in the present invention, it is preferable to provide a cutting step of individually cutting the molten Al alloy member after the shape creation step.

If a cutting process is performed before a shape creation process, the plate-shaped raw material isolate | separated into suitable magnitude | size or length is obtained sequentially. If a cutting process is performed after a shape creation process, the raw material in which the suitable shape was created is obtained sequentially.
This cutting process can be performed using, for example, a cutter or a laser made of a rotary blade or the like. In order to cut without obstructing the flow of the continuous molded body and to make the cut surface relatively clean, it is preferable to use a laser.

(2) Joining process It may be necessary to adhere or bond the ends of the shaped material after the shape creation process. Therefore, although not an essential step of the present invention, when manufacturing a closed cylindrical member (light metal member) from a base material, it is preferable that the present invention includes a joining step of joining the ends of the base material. . Specifically, for example, the shape creation step is a step of forming a plate-shaped material into a substantially tubular shape, and joining the end portions of the shaped material formed into a substantially tubular shape to obtain a tubular molten light metal member It is preferable to provide a process. In order to efficiently manufacture the light metal member, it is preferable that the joining step is provided before the cutting step.

  The joining process can be performed by welding the butt portion (arc, laser, TIG, MIG, etc.), friction stir (FSW) joining, solid phase joining, or the like. Also in this case, it is preferable that the joining light metal member can be manufactured continuously and smoothly when the joining process is performed at a speed corresponding to the speed of the material casting process or the shape creation process.

(3) Heat treatment step The heat treatment step is a step of heating, holding, and cooling the molten light metal member to modify the metal structure of the molten light metal member. There is no limitation on the type of the modification, but there may be strengthening of the raw material or melted light metal member, removal of processing strain, homogenization, and the like. If the light metal is an Al alloy or Mg alloy, the heat treatment process is, for example, homogenization heat treatment, solution treatment, aging treatment (peak aging treatment (T6 treatment / JIS), overaging treatment (T7 treatment / JIS), etc.). is there.

Specific heat treatment conditions vary depending on characteristics to be imparted to the light metal member, the composition of the light metal, and the like. For example, the homogenization treatment is preferably performed at a temperature at which the contained element can diffuse, for example, at a temperature of 400 to 560 ° C. for 10 minutes to 24 hours. In the homogenization treatment, furnace heating or air cooling is performed after heating. On the other hand, the solution treatment is rapidly cooled by water cooling, hot water cooling, oil cooling or the like after such heating.
The aging treatment is cooled after heating for 1 to 10 hours at a lower temperature (for example, 300 ° C. or lower) than the solution treatment or the like, for example. As a result, the internal strain after the solution treatment is removed or the compound particles are precipitated to increase the strength.

  When the light metal is a second-type Al alloy (abrasion resistant Al alloy) described later, Si dissolved in the matrix can be finely precipitated from the matrix by heat treatment. The “primary crystal Si particles” in this specification is a concept including the precipitated Si particles.

《Light metal》
The light metal referred to in the present invention is any one of Al, Al alloy, Mg, or Mg alloy. In the present invention, their specific chemical composition is not a problem. Therefore, a wide variety of light metals that are widely used can be used in the production method of the present invention, and improved materials with improved specific characteristics or newly developed materials can be used. In the following, while taking up a typical Al alloy as a light metal that is relatively easy to improve properties, handleability, etc. and is highly practical, the present inventors have developed a light metal suitable for the production method of the present invention. A detailed description of the Al alloy will also be given.

<General-purpose Al alloy>
A general-purpose Al alloy having a chemical composition suitable for the production method of the present invention may be used according to the characteristics required for the melted light metal member. For example, according to JIS standards, casting materials such as AC4C and AC4CH, 2000 series alloys (Al-Cu series alloys), 5000 series alloys (Al-Mg series), 6000 series alloys (Al-Mg-Si series alloys), 7000 High-strength materials such as Al-Zn-Mg alloys and Al-Li-Cu alloys, as well as general-purpose Al alloys such as Al-Fe alloys, etc. Can be used.

<Type 1 Al alloy>
(1) In addition to such a general-purpose Al alloy, the inventor has newly developed a material suitable for the melted light metal member of the present invention and the manufacturing method thereof. By using this novel Al alloy (this is referred to as “first type Al alloy” in this specification), the above-described excellent effects can be obtained, and the melted light metal member has strength, corrosion resistance, and softening resistance. It can be excellent in properties and the like.
More specifically, the first type Al alloy has a total content of 100%, Fe: 0.8 to 5% as the first component element, and Ti: 0.15 as the second component element. And at least one third component element selected from the third component element group consisting of Zr, Nb, Hf, Sc and Y and each content being 0.05-2% The total amount (X) is more than Ti and less than Fe (Fe%>X%> Ti%), with the balance being Al and inevitable impurities and / or modifying elements.

The first type Al alloy exhibits excellent castability even if it does not contain Si, and also exhibits excellent heat resistance even if it does not contain Ni or Mn.
And when this first type Al alloy is used, the raw material casting step of the present invention is a melting step of dissolving a light metal at a temperature higher than the liquidus temperature determined from the composition by 20 ° C. or more to obtain a light metal melt, It is preferable to comprise a solidification step in which the light metal melt is rapidly solidified at a cooling rate of 150 ° C./second or more and less than 10000 ° C./second to a temperature that is at least 10 ° C. lower than the solidus temperature determined from the composition in the mold part. .

  Thereby, the melted light metal member excellent in intensity | strength and softening resistance is obtained. For example, a melted light metal member made of a first-type Al alloy has a substantially reduced room temperature hardness even when exposed to a high-temperature environment of 1/2 or more of the solidus temperature determined from its chemical composition. do not do. For this reason, a plate-shaped material, a shaped material or a light metal member (hereinafter collectively referred to as “first-type Al alloy material”) made of a first-type Al alloy is reheated to a high temperature of, for example, 200 ° C. or more and age-hardened. If they are equal, the strength can be further improved. Therefore, even if the first type Al alloy material is further subjected to hot working or heat treatment after the shape creation process, the strength of the first type Al alloy material is not lowered, but rather the strength is improved. Is possible.

The reason is considered as follows.
First, when Fe is added to the Al alloy as in the first type Al alloy, from the viewpoint of metal structure, the α phase composed of the Al base and the eutectic structure of the Al-Fe-based compound and the Al base. And a layered phase formed so as to surround the α phase. Furthermore, when the second component element Ti and the third component element are added in specific amounts, the second component element and the third component element can be dissolved in Al, and an Al base made of a supersaturated solid solution is formed. The Therefore, when thermal energy or strain energy is applied, a stable compound (intermetallic compound) phase composed of Al, Ti (second component element), and third component element is precipitated in the Al matrix. Therefore, it seems that the softening resistance was improved and the strength after processing or heating was able to be improved.

(2) Additional configuration Based on the above view regarding the first type Al alloy material, the following steps and the like can be further added to the configuration of the present invention.
(i) It is preferable to have a hot rolling step of reducing the thickness of the first type Al alloy material by 30% or more by performing hot rolling on the first type Al alloy material at a temperature of 200 ° C. or higher. .

(ii) Cold rolling the first type Al alloy material to reduce the thickness of the first type Al alloy material by 30% or more, and then ½ or more of the melting point of the first type Al alloy And it is suitable to have the cold rolling-heating process heated at the temperature of 550 degrees C or less.

(iii) It is preferable to have a heat treatment step of heating the first type Al alloy material at a temperature of 400 ° C. or more for 0.5 hours to 3 hours.

(iv) The first type Al alloy material has an α phase composed of an Al base and a layered phase formed so as to surround the α phase and composed of a eutectic structure of the Al base and the Al—Fe-based compound. It has a metal structure, the Al base is made of a supersaturated solid solution of Al, and the second component element and the third component element are in solid solution in the supersaturated solid solution. In an arbitrary cross section of the first type Al alloy material, Al and It is preferable that the area ratio occupied by a crystallized substance having a particle diameter of 5 μm or more, which is composed of an intermetallic compound of the second component element and the third component element, is less than 5%.

(v) The first type Al alloy material has an α phase composed of an Al base and a layered phase formed so as to surround the α phase and composed of a eutectic structure of the Al base and the Al—Fe-based compound. The Al base is made of a supersaturated solid solution of Al in which the second component element and the third component element are dissolved in Al and / or Al. The Al base includes Al, the second component element, and the third element. It is preferable that precipitates having a particle diameter of 2 to 500 nm made of intermetallic compounds with component elements are dispersed.

(3) Specific Form A preferred specific form for the first type Al alloy will be described.
(i) Fe as the first component element is preferably 0.8 to 5%.
If Fe is insufficient, sufficient strength cannot be obtained, and strength and heat resistance in a high temperature environment may be lowered. On the other hand, if Fe is excessive, the characteristics are likely to change greatly corresponding to the cooling rate, and it becomes difficult to stably produce a cast material having a certain characteristic. Specifically, for example, when rolling is performed, cracks are likely to occur in the first type Al alloy material. Further, coarse crystallized products are easily formed during casting, and workability and formability can be reduced. The Fe content is preferably 2 to 4%, more preferably 3 to 4%.

(ii) Ti as the second component element is preferably 0.15 to 1%.
When Ti is added together with the third component element, the alloy structure can be refined. In addition, when solidified in a supersaturated state when solidified from a molten state or hot-rolled after cold rolling, Ti precipitates in the Al matrix and further improves the strength.
When Ti is too small, sufficient heat resistance and softening resistance cannot be obtained. On the other hand, when Ti is excessive, coarse Al—Ti crystallized substances are easily formed during casting, and workability and formability may be reduced. The Ti content is preferably 0.3 to 0.9%, more preferably 0.7 to 0.8%.

(iii) The third component element contains 0.05 to 2% of individual content of one or more elements selected from the third component element group consisting of Zr, Nb, Hf, Sc and Y.
By adding the third component element together with the first component element Fe and the second component element Ti, an effect of improving the softening resistance is exhibited. That is, when the first component element Fe is added to the Al alloy, a layered phase is formed by the Al—Fe compound and the Al base as described above. Further, when a specific amount of the second component element Ti and the third component element is added, a stable compound (intermetallic compound) phase composed of Al, Ti, and the third component element is added to Al when heat energy or strain energy is applied. Since it precipitates in the matrix phase, strength properties and softening resistance can be improved. Therefore, the strength can be improved when heating is performed after hot rolling or cold rolling. Further, when only the heat treatment is performed without performing the rolling process, the effect of improving the strength can be obtained similarly.

  When the individual content of the third component element group is too small, the above-described effects due to the addition of the third component element cannot be sufficiently obtained. On the other hand, if there is an excessive amount of at least one kind of the third component element, a large crystallized product tends to be produced unless the cooling rate is sufficiently increased, and the workability and formability deteriorate. The individual content of the third component element group is preferably 0.2 to 1.2%, more preferably 0.5 to 1.2%.

Further, the total content X% of the third component element is such that when the content of the first component element Fe in the Al alloy is Fe% and the content of the second component element Ti is Ti%, Fe>X> Ti Satisfied.
In the case of X ≧ Fe, the strength of the first type Al alloy material may be reduced, or the softening resistance may be reduced. In the case of X ≦ Ti, the softening resistance can be deteriorated. In the case of Fe ≦ Ti, the strength of the first type Al alloy material may be reduced, or the softening resistance may be reduced.

  In the third component element group, at least Zr is preferably contained in an amount of 0.2 to 1.2%. In this case, excellent strength characteristics and moldability can be maintained, and softening resistance can be further improved. If the Zr content is too small, the above-described effects due to the addition of Zr cannot be obtained sufficiently. On the other hand, if Zr is excessive, the melting temperature when the Al alloy is melted in the melting step can be very high. Therefore, a special apparatus is required at the time of melting, and the manufacturing cost can be increased.

(iv) In the dissolution step, it is preferable that 0.05 to 2% of Mg is contained as the fourth component element. In this case, the strength of the first type Al alloy material can be further improved without impairing formability. If the amount of Mg is too small, the strength improvement due to Mg cannot be sufficiently obtained. On the other hand, if Mg is excessive, the workability of the first-type Al alloy material is deteriorated. For example, rolling cracks are generated during rolling, and the formability can be lowered. The Mg content is preferably 0.2% to 1.5%, more preferably 0.3% to 0.8%.

(v) In the melting step, it is preferable to contain 0.05 to 1% of one or more fifth component elements selected from the fifth component element group consisting of Cu, Cr, and Co.
When Cu is contained in the fifth component element group, the strength can be improved without substantially impairing the workability of the first type Al alloy material. Further, when Cr and / or Co is contained in the fifth component element group, an Al— (Fe, Cr) compound and / or Al— (Fe, Co) compound is formed, and the Al—Fe compound alone is formed. Elongation, workability, and moldability can be improved rather than dispersing. As a result, the strength of the first type Al alloy material can be improved without substantially impairing workability and formability.

If the fifth component element is too small, the above-described effects due to the addition of the fifth component element cannot be sufficiently obtained. On the other hand, if Cu is excessive in the fifth component element group, workability and formability deteriorate. In this case, the corrosion resistance can be deteriorated. Further, if the Cr and / or Co is excessive in the fifth component element group, the formability is deteriorated. More preferably, the content of the fifth component element is 0.1% to 0.7%, and more preferably 0.1% to 0.5%.
In addition, when 2 or more types of 5th component elements are contained, it is preferable to make the total amount into the said range of 0.05 to 1%.

(vi) In the melting step, it is preferable that V and / or Mo is further contained as a sixth component element in an amount of more than 0.05% and less than 0.5%. In this case, the strength can be improved without substantially impairing the workability and formability of the first type Al alloy material.
If the sixth component element is too small, the effect cannot be obtained sufficiently, and if it is too large, the melting temperature will rise remarkably. Further, coarse crystallized products are easily formed, and workability and moldability are deteriorated. The content of the sixth component element is more preferably 0.1 to 0.4%, and further preferably 0.1 to 0.3%. When two types of sixth component elements are contained, the total amount is preferably 0.05% to 0.5%.

(vii) The total amount of the fourth component element, the fifth component element and the sixth component element is preferably 3% or less. If the total amount thereof is excessive, the workability of the first type Al alloy material is deteriorated, and for example, rolling cracks may occur during rolling. In this case, a crystallized product is easily generated in the material casting process, and the moldability can be deteriorated.

  Further, in the melting step, the first type Al alloy molten metal is obtained by melting at a temperature higher than the liquidus temperature determined from its composition by 20 ° C. or higher (liquidus temperature + 20 ° C. or higher). If the melting temperature is too low, sufficient hot metal flowability cannot be obtained, and a nest is formed inside the first type Al alloy material after casting, so that a healthy first type Al alloy material cannot be obtained.

(viii) Next, in the raw material casting step, the molten metal is cooled at a rate of at least 10 ° C. lower than the solidus temperature determined from the composition of the first type Al alloy, that is, at least at the solidus temperature of −10 ° C. It is preferable to obtain a plate-shaped material of the first type Al alloy by casting into a plate shape while cooling at 150 ° C./second or more and less than 10,000 ° C./second.

If the cooling rate in the raw material casting process is too low, coarse crystallized products are formed during the solidification process, so that the formability may deteriorate, and the strength characteristics and softening resistance may deteriorate. Further, in order to realize a cooling rate exceeding 10,000 ° C./second, a special apparatus is required, so that the manufacturing cost can be increased. In order to achieve a cooling rate exceeding 10,000 ° C./second, it is necessary to considerably reduce the thickness of the first Al alloy plate material after casting.
If the cooling rate is within the above range, the amorphous phase is not substantially formed in the cross section of the plate-shaped material of the first type Al alloy, and, for example, a thermal characteristic that hardly causes a characteristic change before and after the crystallization temperature occurs. A highly stable plate-like material can be obtained.

Further, in the raw material casting process, when the cooling at the cooling rate is not performed until the solidus temperature reaches −10 ° C., the downstream casting material is locally remelted by the heat of the upstream molten metal during continuous casting, Coarse crystallization is formed. Therefore, the metal structure of the obtained Al alloy cast material can be non-uniform.
The cooling at a cooling rate (150 ° C./second or more and less than 10000 ° C./second) may be performed at least until the solidus temperature reaches −10 ° C., and after reaching the temperature, 150 ° C./second or more and 10,000. The cooling may be performed at a temperature deviating from the cooling rate of less than ° C / second.
Cooling at a cooling rate (150 ° C./second or more and less than 10,000 ° C./second) is preferably performed until the solidus temperature reaches −100 ° C.

(Ix) In the raw material casting step, it is preferable to continuously cast the molten metal into a plate shape having a thickness of 0.3 to 10 mm.
When the plate thickness is too small, it becomes difficult to pour molten metal between the rolls or control the gap, and it becomes difficult to produce the first type Al alloy material. On the other hand, if the plate thickness is excessive, it is difficult to ensure a cooling rate of 150 ° C./second or more. In addition, the cooling rate is likely to vary, making it difficult to obtain a plate material of the first type Al alloy having uniform characteristics.

(x) In the present invention, the hot rolling step is not essential. But when performing a hot rolling process, it is preferable to perform a hot rolling process with respect to the plate-shaped raw material after a raw material casting process. Thereby, it is not necessary to heat separately, and man-hours and manufacturing time can be reduced, and manufacturing cost can be reduced. As for the temperature of the plate-shaped raw material in this hot rolling process, 200-500 degreeC is preferable. If this temperature is too low, cracks or the like may occur, and if it is too high, the Al—Fe-based compound in the layered phase becomes coarse and the strength can be lowered. Further, in this case, damage to the roll is increased during the hot rolling process, resulting in a reduction in roll life.

  In the case of the first type Al alloy, the “temperature lower by at least 10 ° C. than the solidus temperature” does not become 500 ° C. or less. Therefore, even when cooling to 500 ° C. in the casting step, sufficient cooling to the above “temperature lower than the solidus temperature by at least 10 ° C.” is ensured. Further, even after high temperature annealing such as 450 ° C. × 1 h after hot rolling, the softening resistance hardly changes anymore.

<Type 2 Al alloy>
(1) In addition to the general-purpose Al alloy and the first type Al alloy as described above, the present inventor proposed a novel Al alloy suitable for a melted light metal member (this is referred to as “second type Al alloy” in the present specification). Developed). If this 2nd type Al alloy is used, the melted light metal member excellent in abrasion resistance can be obtained at a cost much lower than the conventional sintered material and sprayed material.
Specifically, in the second type Al alloy, when the light metal is 100% (hereinafter simply referred to as “%”), silicon (Si): 17 to 43% and copper (Cu ): 0.2 to 7%, Magnesium (Mg): 0.05 to 4%, and the balance consists of Al, inevitable impurities and / or modifying elements.

  And the plate-shaped raw material, raw material, or light metal member (hereinafter collectively referred to as “second-type Al alloy material”) made of the second-type Al alloy has an average particle diameter in a circle equivalent diameter of 5 to 50 μm. It has a metal structure composed of primary crystal Si particles and a matrix that holds the dispersed primary crystal Si particles in at least the surface layer portion, and can exhibit excellent wear resistance.

  The equivalent circle diameter is a diameter when the area occupied by the primary crystal Si particles obtained when the metal structure is observed with a microscope is converted into an equivalent circle area. Specifically, a microphotograph can be easily obtained by image processing or the like. Since the primary crystal Si particles and the matrix clearly differ in contrast on the micrographs, various image measurement processes are performed after the binarization process. In addition, the average particle diameter is an average of equivalent circle diameters within a fixed field of view (specifically, a field of view of about 2700 μm × about 2000 μm is 5 or more fields).

The reason why the second type Al alloy material exhibits excellent wear resistance despite the low cost is not necessarily clear, but at present, it is considered as follows.
The second type Al alloy material is different from gravity casting or die casting in which molten metal is poured into a general mold part even if it is a molten material. That is, a plate-shaped material cast by a roll casting machine is formed. For this reason, from the stage of the plate-shaped raw material before forming, at least on the surface layer portion thereof, a fine metal structure formed by rapidly solidifying the second type Al alloy molten metal is formed. Moreover, in the present invention, while considering that a fine metal structure is formed using a roll casting machine in this way, by further adjusting the composition of the Al alloy molten metal, the metal structure is merely fine. However, it has succeeded in obtaining a metal structure having excellent wear resistance in which primary Si particles are finely crystallized and dispersed in a strong matrix. Thus, the second type Al alloy material has achieved excellent wear resistance while being manufactured at low cost.

  Moreover, in the present invention, after the plate material is cast by the roll casting machine, the plate material made of the second type Al alloy is continuously formed. For this reason, even if it does not heat a plate-shaped raw material anew, at least warm forming is possible using the preheating at the time of casting. For this reason, even if it is a plate-like material in which a large number of hard primary crystal Si particles are dispersed and originally difficult to form, it can be formed at low cost without causing cracks.

  And compared with the conventional manufacturing method which conveys the raw material (board | plate material and casting) manufactured in another place, and forms it sequentially, in the case of this invention, the raw material casting process and the shape creation process of the raw material are the same. Since it can be performed continuously at the same time at the same place, the time and cost related to transportation, setup, preheating, etc., which are conventionally required, can be greatly reduced.

  In this way, the second type Al alloy material is not only excellent in wear resistance at low cost, but also by increasing the efficiency from the material production to the product, so that it can be manufactured at low cost and in large quantities. It can be produced.

  The “abrasion resistance” in the present specification can be objectively or relatively compared by measuring a general wear test such as a ball-on-disk, a pin-on-disk, or a ring-on-disk. However, even if such a test is not performed, the metal structure is observed with a microscope or the like based on the common general knowledge or the experience of those skilled in the art, and the average particle size and dispersion state of primary Si particles (number of particles, uniformity, The particle shape, area ratio, etc.) or the solidified structure of the matrix can also be evaluated. For example, when a certain amount of primary Si particles are crystallized or precipitated finely and uniformly, and the matrix is also fine and strong, and does not contain extra crystallized materials that reduce toughness, etc. It can be determined that the metal structure is excellent in wear resistance.

(2) Chemical composition The second type Al alloy according to the present invention contains Si, Cu, Mg and Al as basic elements.
(i) Si
Si is an important element for crystallizing Si particles that exhibit wear resistance. In particular, in the second type Al alloy, the amount of Si in the Al alloy molten metal is increased so as to have a hypereutectic composition as a whole, thereby facilitating crystallization of a large number of fine primary crystal Si particles.

  If the amount of Si is too small, the amount of primary crystal Si particles to be crystallized is small and sufficient wear resistance cannot be obtained. An excessive amount of Si is not desirable because it increases the aggressiveness to the wear-resistant material (the counterpart material) and deteriorates the workability. Furthermore, when the amount of Si is excessive, the melting temperature becomes too high, and it becomes difficult to obtain a plate-like material having a desired fine metal structure.

  From this point of view, in the second type Al alloy, the amount of Si in the Al alloy is 17 to 43%. The upper and lower limits can be arbitrarily selected within the numerical range. In particular, it is preferable to set numerical values arbitrarily selected from 18%, 19%, 22%, 24%, 30%, 35%, 37%, 38%, 40%, 41%, and 42% as the upper and lower limits.

(ii) Cu and Mg
Cu and Mg are elements that reinforce the matrix holding primary crystal Si particles. In order for the second type Al alloy material to exhibit stable wear resistance, not only the presence of the primary crystal Si particles, but also the enhancement of the strength of the matrix holding the primary crystal Si particles is important. Thereby, the mechanical strength of the second type Al alloy material itself can be improved at the same time. If the amount of such elements is too small, improvement in strength cannot be expected. If the amount is too large, the strength becomes too high, and it becomes difficult to continuously form a plate-like material after casting.

  From such a viewpoint, in the second type Al alloy, the amount of Cu in the Al alloy is set to 0.2 to 7%. The upper and lower limits can be arbitrarily selected within the numerical range. Especially from 0.3%, 0.4%, 0.6%, 0.8%, 1%, 2%, 3%, 4%, 5%, 5.5%, 6%, 6.5% It is preferable to use arbitrarily selected numerical values as upper and lower limits.

  Similarly, in the second type Al alloy, the amount of Mg in the Al alloy is set to 0.05 to 4%. The upper and lower limits can be arbitrarily selected within the numerical range. In particular, a numerical value arbitrarily selected from 0.07%, 0.1%, 0.5%, 0.8%, 1.5%, 2%, 2.5%, 3%, 3.5% The lower limit is preferable.

(iii) P
P is an element effective for finely and spheroidizing primary Si particles crystallized from a high Si Al alloy molten metal. As the primary crystal Si particles are finer and spherical, the second type Al alloy material having better wear resistance can be obtained.
If P is too small, such an effect cannot be obtained, and if it is excessive, improvement in fine spheroidization cannot be expected, and the raw material cost increases.

  From such a viewpoint, in the second type Al alloy, it is preferable that the amount of P in the Al alloy is 20 to 400 ppm by mass ratio. The upper and lower limits can be arbitrarily selected within the numerical range. In particular, it is preferable to set numerical values arbitrarily selected from 30 ppm, 60 ppm, 100 ppm, 150 ppm, 200 ppm, 250 ppm, 300 ppm, and 350 ppm as the upper and lower limits.

(3) Metal structure The metal structure of the second type Al alloy material is a composite structure in which Si particles are dispersed in a matrix.
The primary crystal Si particles are formed by rapidly solidifying an Al alloy melt having the above composition, and have a great influence on the wear resistance of the second type Al alloy material. In particular, the average particle size is important, and even if the average particle size is too small or too large, sufficient wear resistance cannot be obtained. The average particle diameter of the primary crystal Si particles can be changed depending on the cooling rate of the Al alloy molten metal, but sufficient wear resistance can be obtained when the average particle diameter is 5 to 50 μm in terms of equivalent circle diameter. The upper and lower limits of the average particle diameter can be arbitrarily selected within the numerical range. In particular, it is preferable to set numerical values arbitrarily selected from 7 μm, 10 μm, 15 μm, 20 μm, 30 μm, 40 μm, and 45 μm as the upper and lower limits.

  In addition, when the metal structure is observed with a microscope, the area ratio, which is the ratio of primary crystal Si particles in the metal structure, is preferably 10 to 40%. If the area ratio is too small or too large, sufficient wear resistance or stable slidability cannot be obtained. The upper and lower limits can be arbitrarily selected within the numerical range. In particular, it is preferable to set numerical values arbitrarily selected from 11%, 15%, 30%, 35%, 37%, and 40% as the upper and lower limits.

  The matrix has a composition obtained by removing crystallized Si particles from the Al alloy having the above chemical composition. Therefore, the matrix is made of an Al alloy in which the remaining Si, Cu, and Mg are dissolved, crystallized, or precipitated in Al. In particular, the above-described Cu or Mg affects the characteristics of the matrix, and is important for ensuring the retention of primary crystal Si particles that exhibit wear resistance and the slidability of the second type Al alloy material.

  In addition, although the thickness of the plate-shaped raw material which concerns on this invention is not ask | required, when the subsequent shaping | molding is considered, it is about several mm-about dozen mm normally. The width of the plate material is appropriately determined according to the forming method and the size of the melted light metal member. The shape of the melted light metal member made of the second type Al alloy is not limited, but the range of the shape is a range in which the cast plate-shaped material can be continuously formed. However, secondary molding or the like may be performed separately after the primary molding following the casting of the plate material.

<Applications>
(1) The melted light metal member of the present invention may be used in any shape or form of use, but it exhibits various excellent characteristics. Therefore, the melted light metal member of the present invention is widely used instead of the conventional iron member. It is possible to reduce the weight of various devices. For example, if the cylinder liner of an automobile engine is changed from the conventional graphite cast iron to the melted light metal member of the present invention made of the second type Al alloy, it is expected to improve the fuel consumption and the running performance by reducing the weight. Moreover, cost reduction can be aimed at by changing to the molten light metal member of this invention, such as the conventional sintered member.

(2) The use of the melted light metal member of the present invention according to the type of plastic working is as follows, for example.
(i) Roll forming process Molten light metal members manufactured through roll forming processes include automotive body pillars, bumper reinforcements, internal combustion engine sleeves (liners), side members, side sills, cross members, and ladder frames. There are door beams, etc.
The kind of light metal used in this case is not particularly limited, and for example, any of the general-purpose Al alloy, the first type Al alloy, and the second type Al alloy as described above can be used. In particular, the present invention is preferably a roll forming step in which the plastic forming in the shape creation step is roll forming.

(ii) Press work Melted light metal members manufactured through press work include automobile hoods (trunks, bonnets, etc.), floor panels, center pillars, subframes, and the like. The kind of light metal used in this case is not particularly limited, but from the viewpoint of the strength, rigidity, and toughness (= impact absorbability) of the member, it is particularly preferable to use either the first type Al alloy or the general-purpose Al alloy.

(iii) Punching process, burring process or hemming process As the melted light metal member manufactured through the punching process, burring process or hemming process, there are various link members, arm members, and the like. The type of light metal used in this case is not particularly limited, but it is particularly preferable to use the first type Al alloy from the viewpoint of the strength, rigidity, and toughness (= impact absorbability) of the member.

The present invention will be described more specifically with reference to examples.
"Manufacturing equipment"
<Basic form>
As an example of the melted light metal member according to the present invention, a cylindrical member L was manufactured using a casting apparatus A shown in FIG. For example, the cylindrical member is assumed to be a cylinder liner that is press-fitted into a cylinder of an automobile engine and is in sliding contact with the piston.
The casting molding apparatus A includes a twin roll caster 1 (a twin roll casting machine), a roll forming machine 2, a laser welding machine 3, and a cutter 4.

The twin roll caster 1 includes a molten metal pool 10, a pair of cooling rolls 11, 12, a cooling device (not shown) for cooling the cooling rolls 11, 12, and a driving device (not shown) for rotating the cooling rolls 11, 12. Z). In addition, although each rotating shaft of the cooling rolls 11 and 12 is arrange | positioned horizontally, the cooling roll 11 and the cooling roll 12 are each arrange | positioned at the perpendicular direction. The molten metal pool 10 is horizontally arranged so that the Al alloy molten metal M is supplied toward the gap (roll kiss point) between the cooling rolls 11 and 12. The Al alloy molten metal M is continuously replenished from a melt replenishing nozzle (not shown) so that the molten metal surface of the molten metal reservoir 10 is within a predetermined range.
The outer peripheral surface side of the cooling rolls 11 and 12 is a copper mold part made of a flat annular band. The copper mold part is always cooled and cooled from the inner peripheral surface side by cooling water sprayed on the inner peripheral surfaces of the cooling rolls 11 and 12.

  The roll forming machine 2 is provided with a plurality of forming rollers 21 for forming a thin plate material R (plate material, flat plate material) that has come out of the twin roll caster 1 into a cylindrical shape with the feeding direction as an axis. Become. Each forming roller 21 can be rotated or driven independently. The feeding speed of the thin plate material R is adjusted according to the speed of the cooling rolls 11 and 12.

  The laser welding machine 3 irradiates the end part of the substantially tubular thin sheet material R coming out of the roll forming machine 2 in the vertical direction (feeding direction), and melts and joins the end part. Note that both ends of the roll forming machine 2 are in contact with each other when the roll forming machine 2 is removed.

  The cutter 4 cuts the pipe material welded at both ends by the laser welding machine 3 according to a desired height of a cylinder liner or the like. The cutter 4 was a high-speed cutter that cuts the object by applying a blade rotated at high speed to the object. In this way, the cylindrical member L is obtained sequentially and continuously.

<Deformation 1>
FIG. 2 shows a casting apparatus B in which the roll forming machine 2 of the casting apparatus A described above is changed to a roll forming machine 102. By this casting apparatus B, a square (groove shape) member F is manufactured as an example of the melted light metal member according to the present invention. In addition, the same code | symbol was used in FIG. 1 and FIG. 2 about each member which has not changed from each member shown in FIG.
Specifically, the roll forming machine 102 of the casting apparatus B forms the thin plate material R (plate material) that has come out of the twin roll caster 1 into a square shape (channel shape) with the feed direction as an axis. Therefore, a plurality of forming rollers 121 are arranged. Others are the same as in the case of the casting apparatus A.

<Modification 2>
In FIG. 1 or FIG. 2, the twin roll caster 1 from which the flat plate-shaped raw material (flat plate-shaped material) with the outer peripheral surface of the cooling rolls 11 and 12 being flat annular strips with a constant plate thickness in the width direction is obtained. showed that. On the other hand, the cooling rolls 211 and 212 of the twin roll caster 2 in which the outer peripheral surface shape (mold part shape) of the cooling roll is changed are shown in FIG. The center of the outer peripheral surface of the cooling roll 211 is a male mold having a convex arc shape in the cross section, and the cooling roll 212 is a female mold having a concave section in the center of the outer peripheral surface. By arranging these cooling rolls 211 and 212 in a fitting manner, an arcuate cavity C is formed in the central portion of the outer periphery where they face each other. When this twin roll caster 2 is used, a continuous semi-cylindrical bowl-shaped material having a semicircular cross section shown in FIG. 4A is obtained.
By further forming this bowl-shaped material into a desired shape with a roll forming machine, various melted light metal members according to the present invention can be obtained.

<Modification 3>
Furthermore, by making the cooling rolls 211 and 212 into a male mold and a female mold having a square cross-sectional shape at the center of the outer peripheral surface, a square cavity C is formed, and the cross section as shown in FIG. A continuous channel-shaped bowl-shaped material having a square groove shape is obtained.

<Manufacture of test pieces>
<Examination of Type 1 Al Alloy>
When manufacturing a melted light metal member using the casting molding apparatus A described above, first, development study of an Al alloy (first type Al alloy) effective for improving the characteristics of the melted light metal member was performed as follows. .
First, as shown in Table 1-1 to Table 1-4, a first type Al alloy material (plate-like material or shaped material) made of an Al alloy having a plurality of types of compositions is prepared, and its softening resistance and the like are determined. The investigation revealed its superiority. Table 1-1 and Table 1-2 show the alloy component composition, specific gravity, and cooling rate of the first type Al alloy materials (Examples 1 to 48) within the range considered to be preferable. For comparison, an Al alloy cast material (Comparative Examples 1 to 20 and Comparative Examples 28 to 37) made of an Al alloy having a component range other than that and a first type Al alloy material manufactured at a cooling rate that deviates from the preferred range. (Comparative Examples 21 to 27) were also prepared. The component composition and specific gravity of these alloys are shown in Tables 1-3 and 1-4. In this example, the cooling rate was determined by the rate at which it passed through the range of the solidus temperature ± 40 ° C. in the course of cooling the molten Al alloy of each composition in the casting process.

  In this example, as shown in FIG. 1-1, each 1st type Al alloy material (Examples 1-48, Comparative Examples 1-20, and Comparative Examples 28-37) is produced by single roll type continuous casting, and then Various post-treatment steps were performed for softening resistance evaluation.

That is, as shown in FIGS. 1-1 (a) to (c), in producing each type 1 Al alloy material, a temperature (melting temperature) that is 20 ° C. higher than the liquidus temperature determined from each alloy composition. The melting step S1 in which each Al alloy is dissolved to form a molten metal, and the molten metal is cooled to at least 10 ° C. lower than the solidus temperature at various cooling rates shown in Table 1-1 to Table 1-4. Furthermore, it cooled to room temperature, and performed casting process S2 which casts in the plate shape of thickness 1.2mm, and obtains 1st type Al alloy material (plate-shaped raw material).
In the single roll type roll casting machine used in the casting step S2, a copper roll was used as the cooling roll. The melting step and the casting step correspond to the material casting step in the present invention.

  Moreover, post-processing process S3 was performed with respect to each 1st type Al alloy material (Examples 1-48, Comparative Examples 1-20, and Comparative Examples 28-37) obtained after casting process S2. As post-processing process S3, the following hot rolling process S3a (Examples 1-36, Examples 41-48, Comparative Examples 1-20, and Comparative Examples 28-37), Cold rolling-heating process S3b (implementation) Example 37, Example 39, and Example 40) or heat treatment step S3c (Example 38) was performed. Tables 1-1 to 1-4 show the types of post-processing steps performed on each Al alloy cast material.

In the hot rolling step S3a, as shown in FIG. 1-1 (a), the Al alloy cast material after the casting step S2 is heated to a temperature of 450 ° C., and the thickness is reduced by 40% by hot rolling. A 0.72 mm type 1 Al alloy material was obtained. Thereafter, it was allowed to cool to room temperature.
In the cold rolling-heating step S3b, as shown in FIG. 1-1 (b), the first type Al alloy material after the casting step S2 is subjected to cold rolling and the thickness is reduced by 40% to reduce the thickness to 0. A 72-mm first type Al alloy material was obtained. Thereafter, the first-type Al alloy material was heated for 1 hour at a temperature of ½ or more of the melting point of the Al alloy (in this example, 450 ° C.). Thereafter, it was allowed to cool to room temperature.
In the heat treatment step S3c, as shown in FIG. 1-1 (c), the Al alloy cast material after the casting step S2 was heated at a temperature of 450 ° C. for 1 hour. Thereafter, it was allowed to cool to room temperature.

  Furthermore, in this example, as shown to FIGS. 1-1 (a)-(c), after the said post-processing process S3, 1st type Al alloy material is hold | maintained at the temperature of 300 degreeC for 100 hours (for example, engine The heating process S4 which assumed that it exposed to the temperature range equivalent to driving | running | working environment for a long time) and left to cool to room temperature after that was performed. In this way, Al alloy materials (Example 1 to Example 48, Comparative Examples 1 to 20, and Comparative Examples 28 to 37) subjected to the post-processing step S3 and the heating step S4 were obtained after casting.

In this example, in order to show the superiority of the cooling rate, for comparison, an Al alloy having each composition shown in Table 1-4 was cast at a cooling rate of less than 150 ° C. to produce an ingot, The first type Al alloy material was produced by rolling the ingot (Comparative Example 21 to Comparative Example 27).
That is, as shown in FIG. 1-2 (a), in producing the ingot first, the alloy was melted at a temperature (melting temperature) 200 ° C. higher than the liquidus temperature determined from the composition of each alloy. A melting step S5 for producing a molten metal and a solidifying step S6 for solidifying the molten metal by cooling at a cooling rate of 100 ° C./second were performed. This obtained the plate-shaped Al alloy ingot of thickness 1.2mm.

After the ingot production, a hot rolling step S7a or a cold rolling-heating step S7b was performed as a post-processing step S7. Specifically, for Comparative Examples 21 to 23 and Comparative Examples 25 to 27, a hot rolling step S7a was performed, and for Comparative Example 24, a cold rolling-heating step S7b was performed.
In the hot rolling step S7a, as shown in FIG. 1-2 (a), the Al alloy ingot after the solidification step S6 is heated to a temperature of 450 ° C., and the thickness is reduced by 40% by hot rolling. A first type Al alloy material having a thickness of 0.72 mm was obtained. Thereafter, it was allowed to cool to room temperature.

  Further, in the cold rolling-heating step S7b, as shown in FIG. 1-2 (b), the Al alloy ingot after the solidification step S6 is subjected to cold rolling and the thickness is reduced by 40%. A first type Al alloy material having a thickness of 0.72 mm was obtained. Then, it heated for 1 hour at the temperature (450 degreeC in this example) more than 1/2 of melting | fusing point of Al alloy, and stood to cool to room temperature.

Further, as shown in FIGS. 1-2 (a) and (b), after the post-processing step S7, the Al alloy material is held at a temperature of 300 ° C. for 100 hours (for example, in a temperature range corresponding to the engine running environment). The heating step S8 was performed, assuming that it was exposed to time, and then allowed to cool to room temperature.
As described above, the first type Al alloy material (Comparative Example 21 to Comparative Example 27) subjected to the melting step S5, the solidifying step S6, the post-processing step S7, and the heating step S8 was obtained.

In Examples 1 to 40 and Comparative Examples 1 to 27, the hardness HVR1 of the Al alloy cast material before the post-processing step S3 (S7) and the hardness HVR2 of the first type Al alloy material after the post-processing step S3 (S7). And hardness HVR3 of Al alloy material which passed through heating process S4 (S8) after post-processing process S3 (S7) was measured, respectively, and softening resistance was evaluated by the change.
The HVRn (n: No) is referred to as residual hardness. Generally, when it is exposed to a high temperature range exceeding 1/2 of the material melting point, the residual hardness is greatly reduced. From such a point of view, the first type Al alloy material having a small hardness reduction even when exposed to a high temperature range for a long time was examined.

As shown in FIG. 1-3 (a), the softening resistance is excellent (◎) when HVR1 <HVR2 <HVR3 (pattern 1), and HVR1 < A pattern that satisfies HVR2, HVR1 <HVR3, and HVR2> HVR3 (pattern 2) is determined to be good (◯), and other patterns, for example, HVR1>HVR2> HVR3 as shown in FIG. What becomes (pattern 3) is determined as defective (x). The evaluation results of the softening resistance of Examples 1 to 48 and Comparative Examples 1 to 37 are shown in Tables 1-5 to 1-8.
In FIGS. 1-3 (a) to (c), the horizontal axis represents HVR1, HVR2, and HVR3, and the vertical axis represents Vickers hardness HV.

As is known from Table 1-5 and Table 1-6, the first class Al alloy materials of Examples 1 to 48 have the softening resistance indicating the behavior of the pattern 1 or pattern 2, and the softening resistance is improved. It turns out that it is excellent.
On the other hand, as is known from the results of Tables 1-7 and 1-8, in the Al-transition element alloy, depending on the combination of transition element species or the cooling rate at the time of casting, as shown in FIGS. It was found that the patterns are classified into “rising system (◎ or ◯)” indicating patterns 1 and 2 and “descending system (×)” of pattern 3 in FIG. As shown in Table 1-7, the descending system is a phenomenon observed in general-purpose Al alloys.

  In order to investigate the reason why the first-type Al alloy material of Examples 1 to 48 exhibits excellent softening resistance as described above, one type of first-type Al alloy material (Example 11) of these examples is used. The change of the alloy structure before and after the hot rolling process was observed with a scanning electron microscope. A photomicrograph of the alloy structure before hot rolling is shown in FIG. 1-4, and a photomicrograph of the alloy structure after hot rolling is shown in FIG. 1-5. As is known from FIGS. 1-4 and 1-5, after hot rolling, in the metal structure of the α phase composed of Al base and the layered phase composed of eutectic structure of Al—Fe based compound and Al base. A stable compound phase (precipitate) composed of Al, Ti and the third component element was precipitated in the Al base. This stable compound phase (precipitate) improves softening resistance, and it is considered that the strength is improved after processing, heating, and the like as described above.

  In addition, the result (photograph) which observed the alloy structure of the 1st type Al alloy material after rolling with the scanning electron microscope with the magnification different from FIG. 1-5 was shown to FIGS. 1-7. As is known from FIGS. 1-7, the first-type Al alloy material 1 of Example 11 has an α phase 2 made of an Al base and a layered phase 4 formed so as to surround the α phase 2. ing. And in the alloy structure of the 1st type Al alloy material 1 (Example 11) after hot rolling, it turns out that the precipitate 3 with a particle size of about 15 nm or less has arisen in Al base.

  Moreover, another photograph of the scanning electron microscope (SEM) of the alloy structure of the first type Al alloy material of Example 11 before the hot rolling process is shown in FIGS. 1-8 and 1-9. FIG. 1-8 shows a photograph of an alloy structure of an Al alloy cast material (Example 11) observed with a SEM at a magnification of 1000 times, and FIG. 1-9 shows an alloy of the first type Al alloy material (Example 11). The photograph which observed the structure | tissue by SEM of 5000 times magnification was shown. FIG. 1-9 is an enlarged view of the portion where the crystallized product is generated in FIG. 1-8.

For comparison with Example 11, Al in Comparative Example 22 before the hot rolling step
Scanning electron micrographs of the alloy structure of the cast alloy material are shown in FIGS. 1-10 and 1-11. FIG. 1-10 shows a photograph of an alloy structure of an Al alloy cast material (Comparative Example 22) observed with a SEM at a magnification of 1000 times, and FIG. 1-11 shows an alloy of the first type Al alloy material (Comparative Example 22). The photograph which observed the structure | tissue by SEM of 5000 times magnification was shown. FIG. 1-11 is an enlarged view of the portion where the crystallized product in FIG. 1-10 was generated.
In addition, as a scanning electron microscope, S-3600N made from Hitachi, Ltd. was used, and it observed on the conditions of acceleration voltage 15kV.

As shown in FIGS. 1-8 and 1-9, in the alloy structure of the first-type Al alloy material of Example 11, a crystallized substance (Al and the second component element Ti and having a particle size of 5 μm or more in the α phase). There was almost no compound (Alx (Ti, X))) with the third component element X, and the area ratio of the crystallized product was less than 5%.
On the other hand, as is known from FIGS. 1-10 and 1-11, in the alloy structure of the first-type Al alloy material 9 of Comparative Example 22, coarse crystallization with a grain size of 5 μm or more in the Al matrix of the α phase 92. The product 93 (compound of Al, second component element Ti, and third component element X (Alx (Ti, X))) was relatively large (area ratio of 5% or more) and dispersed. Further, as is known by comparing FIGS. 1-9 and 1-11, a larger crystallization product was generated in Comparative Example 22 than in Example 11.

Moreover, the result of having performed the component analysis in the area | region where the crystallization thing of the 1st type Al alloy material (comparative example 22) was observed is shown (refer FIG. 1-12). In the figure, the relative amount of each component (Al, Zr, Ti, Fe) in the region indicated by the straight line AA in the scanning electron micrograph of the first type Al alloy material (Comparative Example 22) is peaked. The size is shown.
In FIG. 1-12, Al, Ti, and Fe show profiles by Kα rays, and Zr shows profiles by Lα rays. As can be seen from FIG. 1-12, in the crystallized product, a large amount of the second component element Ti and the third component element Zr are present, and a compound of Al, Ti, and Zr is formed. In addition, for the analysis of each component amount, an energy dispersive X-ray analyzer manufactured by Edax Japan Co., Ltd. was used.

  Moreover, the result (photograph) which observed the 1st type Al alloy material (Example 11) before hot rolling with the transmission electron microscope (TEM) was shown to FIGS. 1-13. As a transmission electron microscope, HF-2000 manufactured by Hitachi, Ltd. was used, and observation was performed under the condition of an acceleration voltage of 200 kV and a beam diameter of 1 nm. As shown in FIG. 1-13, the metal structure of the first-type Al alloy material 1 of Example 11 has an α phase 2 composed of an Al base and a layered phase 4 formed so as to surround the α phase 2. is doing.

Subsequently, the component element which exists in the layered phase 4 was investigated by performing energy dispersive X-ray analysis (EDX) about arbitrary positions in the layered phase 4 (points * 1 to * 4 in FIG. 1-13). In EDX analysis, NORAN VOYAGER III M3100 was used as an energy dispersive X-ray analyzer, and a Si / Li semiconductor detector was used as a detector. The measurement was performed under the conditions of an energy resolution of 137 eV and an acquisition time of 30 seconds. The results are shown in FIGS.
FIGS. 1-14 to 1-17 show the results of EDX analysis at points * 1 to * 4 in FIG. 1-13, respectively.

Similarly, the first type Al alloy material after hot rolling (Example 11) was also observed with a transmission electron microscope (TEM), and EDX analysis was performed at arbitrary four points * 1 to * 4. A TEM photograph is shown in FIG. 1-18, and the results of EDX analysis at points * 1 to * 4 in FIG. 1-18 are shown in FIGS. 1-19 to 1-22, respectively.
As is known from FIGS. 1-13 to 1-17 and FIGS. 1-18 to 1-22, only Al and Fe are detected in the layered phase 4 irrespective of before and after the hot rolling, The two-component element Ti and the third component element Zr do not exist (see FIGS. 1-13 and 1-18). Therefore, it can be seen that the second component element Ti and the third component element Zr are present in the α base 2 Al base.

  Next, in this example, with respect to Examples 1 to 48 and Comparative Examples 1 to 37, strength at room temperature, workability, formability, and corrosion resistance were evaluated as follows.

<Strength>
A tensile test piece was cut out from each type 1 Al alloy material, and a tensile test was conducted according to JIS Z2241 to obtain a tensile strength. The results are shown in Tables 1-5 to 1-8.
Moreover, the relationship between the tensile strength measured by the tensile test and the cooling rate is shown in FIGS. 1-6. FIG. 1-6 is a semilogarithmic graph in which the horizontal axis indicates the cooling rate (° C./second) and the vertical axis indicates the tensile strength (MPa). And in FIG. 1-6, three types of Al alloy compositions, namely Al-2Fe-1Zr-0.8Ti (Comparative Example 21, Example 48, Example 9, Example 47, Example 46), Al-4Fe -1Zr-0.8Ti (Comparative Example 22, Example 43, Example 11, Example 42, Example 41), Al-4Fe-1Zr-0.8Ti-0.5Mg (Example 45, Example 44) The relationship between the cooling rate and the tensile strength of the first type Al alloy material was shown.

<Processability>
The determination of workability was performed by observing the presence or absence of occurrence of rolling cracks after rolling (hot rolling or cold rolling). That is, the surface of each first-type Al alloy material after the rolling process is observed, and the case where rolling cracks are observed on the surface is evaluated as bad (x), and the case where no rolling cracks are observed is evaluated as good (◯). did. In addition, about the continuous cast material which only the ear crack (crack generate | occur | produced in the both ends of a continuous cast material) generate | occur | produced, it evaluated as favorable ((circle)). This is because it can be removed by a slitter in the actual process. The results are shown in Tables 1-5 to 1-8. In addition, about the 1st type Al alloy material (Example 38) which is not rolling, evaluation of workability is not performed.

<Moldability>
As for formability, a hemming limit evaluation test of an automotive Al alloy plate specified in JIS H7701 was performed, and the occurrence of surface cracks in the bent portion was observed with a stereoscopic microscope. The case where a crack was observed on the surface was evaluated as bad (x), and the case where no crack was observed was evaluated as good (◯). The results are shown in Tables 1-5 to 1-8.

<Corrosive>
Corrosion was evaluated by performing a corrosion test on 6061 alloy and comparing the result.
That is, first, a test piece having a certain size was cut out from a commercially available 6061 alloy (Al-1.1Mg-0.8Si-0.1Cu-0.1Cr-0.03Ti), and its weight W1 was measured.

  Next, a salt spray test was performed on the test piece using a 5 wt% NaCl aqueous solution (JIS Z2371). Furthermore, after removing the corrosion products generated on the surface of the test piece, the weight (W2) of the test piece was measured. Then, the weight change rate ΔWa (%) of the test piece of 6061 alloy was calculated based on the equation: ΔWa = | W2-W1 | × 100 / W1.

On the other hand, also about the 1st type Al alloy material of Examples 1-48 and Comparative Examples 1-37, the test piece of a fixed dimension is produced from each Al alloy casting material, and the salt spray test similarly to the case of the above-mentioned 6061 alloy Went. Then, the weight W3 before the test and the weight W4 after the test were measured, and the weight change rate ΔWb% of each test piece was calculated based on the equation: ΔWb = | W4-W3 | × 100 / W3.
The determination of corrosiveness was determined to be excellent (◎) when ΔWb <0.8ΔWa and good (◯) when 0.8 Wa ≦ Wb ≦ 1.2 Wa. Moreover, the case of (DELTA) Wb> 1.2 (DELTA) Wa was set as the defect (x). The results are shown in Tables 1-5 to 1-8.

  As can be seen from Table 1-5, Table 1-6, and FIGS. 1-6, Examples 1 to 48 show sufficient strength of a tensile strength of 230 MPa or more, as well as softening resistance, moldability, and resistance to resistance. It turns out that it is an Al alloy casting material excellent also in corrosivity.

  As can be seen from the results of Examples 1 to 48 (Tables 1-5 and 1-6), the second component element Ti and the third component elements (Zr, Nb) were used for the base Al—Fe alloy. , Hf, Sc, Y), a high-strength Al alloy is obtained without impairing formability and corrosion resistance. Moreover, the characteristics can be further improved by adding a fourth component element Mg, a fifth component element (Cu, Cr, Co), and a sixth component element (V, Mo) as necessary.

  Moreover, Example 1- Example 48 was excellent in softening resistance, and also discovered that it further strengthened by giving a thermal energy and a strain energy in a post process. And the characteristic deterioration is very little in the use environment (for example, it exposes to 300 degreeC for a long time). Therefore, the first type Al alloy can be suitably used in, for example, automobile parts.

  On the other hand, as is known from Tables 1-7 and 1-8, when an Al alloy exceeding the alloy composition range specified in the present invention was used (Comparative Examples 1 to 20, Comparative Examples 28 to 37) ) Or when the cooling rate is insufficient (Comparative Examples 21 to 27), it can be seen that the characteristics of the alloy casting material are deteriorated.

  In this example, the relationship between the annealing (heating) temperature and the residual hardness of the first type Al alloy material that was cold-rolled after the casting process and the first type Al alloy material that was not rolled. Examined. Specifically, first, an Al alloy cast material was produced under the same composition and conditions as in Example 11 (see Table 1-1). Next, the first type Al alloy material was cold-rolled at room temperature to reduce the thickness of the first type Al alloy material by 50%. Next, heating (annealing) was performed at a predetermined temperature for 1 hour, and the residual hardness of the first type Al alloy material after heating was examined. And the relationship between heating (annealing) temperature and residual hardness was plotted on the graph. The results are shown in FIG. The residual hardness was measured using a Vickers hardness tester under the conditions of a load of 100 gf and a holding time of 20 seconds.

  In addition, heating (annealing) was also performed in the case where the Al alloy cast material produced under the same composition and conditions as in Example 11 (see Table 1-1) was annealed at each temperature without rolling. ) The relationship between temperature and residual hardness was plotted on a graph. The results are shown in FIG.

  As can be seen from FIG. 1-23, the residual hardness can be improved by heating in any case where heating is performed after rolling and heating is performed without rolling. In particular, when heated at 400 ° C. to 500 ° C., the residual hardness can be sufficiently improved, and when rolling is performed, when heated at 400 ° C. to 450 ° C., the residual hardness is further increased. It can be seen that this can be improved.

<Examination of Type 2 Al Alloy>
Using the above-described casting apparatus A, various test pieces (cylindrical members L) having different Al alloy compositions were manufactured. The composition of each test piece is shown in Table 2-1 (test piece Nos. A1 to A31) and Table 2-2 (test piece Nos. B1 to B9). For comparison, a test piece was similarly manufactured using a thin plate material manufactured by gravity casting instead of twin roll casting. Each composition at this time is shown in Table 2-3 (test pieces No. C1 to C31).

  Here, the twin roll casting was performed by pouring a molten Al alloy (molten metal temperature 800 ° C.) having the composition shown in Table 1 into a twin roll caster 1 composed of a copper cooling roll. At this time, the rotation speed of the cooling rolls 11 and 12 was set to 5 m / min, and the distance between both cooling rolls was adjusted so that the plate thickness was 5 mm. In addition, gravity casting was performed by pouring a molten Al alloy (melt temperature 800 ° C.) having a composition shown in Table 2-3 into a mold having a plate-like cavity having a thickness of 5 mm and naturally cooling.

  In addition, when the present inventor observed the cross-sectional structure of the obtained plate, the secondary dendrite interval was determined by the DAS method, the cooling rate when twin roll casting was about 170 ° C./second, in the case of gravity casting The cooling rate was about 7 ° C./second.

<Measurement>
(1) The metal structure photograph observed with the optical microscope about each said test piece was image-analyzed, and the circle | round | yen equivalent diameter and area ratio of primary-crystal Si particle | grains were calculated | required. The size of the area subjected to image analysis was about 2700 μm × about 2000 μm.
(2) About each test piece, the Vickers hardness was measured. The measurement conditions at this time were a load of 5 kgf and a holding time of 30 s.

<Observation of metal structure>
A plate-shaped material was manufactured by twin roll casting or gravity casting of Al-20% Si-4% Cu-1% Mg (-0.02% P)% Al alloy molten metal. The casting conditions for twin roll casting and gravity casting are as described above.

  The structure | tissue photograph which observed these plate-shaped raw materials with the optical microscope was shown to FIGS. 2-1 to 2-3. For reference, the average particle size and Vickers hardness of primary crystal Si particles of these plate materials were determined by the method described above, and the results are also shown in Table 2-4.

<Evaluation>
(1) In the case of twin roll casting (test pieces No. A1 to A31, B1 to B9, D1 and D2)
(i) From Table 2-1, Table 2-2, and Table 2-4, all of the test pieces obtained by twin-roll casting the molten Al alloy within the chemical composition referred to in the present invention have an average primary Si particle size. It is in the range of 9 to 36 μm, and it can be seen that the primary crystal Si particles are finely dispersed. This average particle size tended to increase with an increase in the amount of Si, but was still in the range of 21 to 36 μm in Table 2-1, and in the range of 9 to 16 μm in Table 2-2. From this, it was confirmed that even when the Si amount is increased, fine primary crystal Si particles are stably crystallized by performing twin roll casting. In particular, as is clear from Table 2-2, it was found that very fine primary crystal Si particles were stably dispersed by containing a small amount of P. This is obvious from metal structure photographs that differ only in the content of P, as shown in FIGS. 2-1 and 2-2.

  Furthermore, the primary Si particles dispersed in the matrix are not only small in average particle size. That is, the area ratio indicating the dispersion ratio was 11 to 33% of the total, and all were as high as 10% or more. Therefore, it can be seen that the crystallization of fine Si particles is sufficiently secured. It has also been clarified that the ratio of the area ratio can be increased by increasing the total amount of Si.

  Moreover, the hardness of this test piece exists in the range of 101-238Hv, and it turned out that all have sufficient hardness of 100Hv or more. Thereby, it turns out that sufficient abrasion resistance is expressed. Note that the Vickers hardness increases as the area ratio of the primary crystal Si particles increases (the larger the total amount of Si contained). Furthermore, it was found that the Vickers hardness increases as the Cu or Mg content increases with the same area ratio. Furthermore, if the overall composition of Si, Cu and Mg was the same, the smaller the average particle size of the primary crystal Si particles, the greater the Vickers hardness.

(ii) However, the test piece No. shown in Table 2-1. The following can be understood from the data of A28 to A31.
Even when the amount of Si was 15% (<17%), which is a general hypereutectic composition, the area ratio was smaller than 10% and the Vickers hardness was smaller than 100 Hv (test piece No. A28). Conversely, when the Si amount increases to about 45%, both the area ratio and Vickers hardness increase, but it is difficult to say that the primary crystal Si particles are finely dispersed and stable wear resistance cannot be expected. (Test piece No. A29).

  Moreover, even if the amount of Si was an appropriate amount, when Cu and Mg were not contained at all, the hardness or strength of the matrix was insufficient, and the overall Vickers hardness was insufficient (test piece No. A30). On the contrary, when the content of Cu or Mg increases, the average particle diameter, area ratio, and Vickers hardness of the primary crystal Si particles are improved, but the matrix becomes too hard and cracks occur during molding.

(2) In the case of gravity casting (test pieces No. C1-C3, D3)
Compared with the above-mentioned twin-roll cast test piece, the gravity cast test piece has good area ratio of primary crystal Si particles and Vickers hardness, but the average particle size of primary crystal Si particles is all Considering the drop of Si particles and the aggressiveness to the mating material, excellent wear resistance cannot be exhibited. This is apparent from the metal structure shown in FIG.

It is a whole schematic diagram which shows the casting apparatus which manufactures the cylindrical molten light metal member which concerns on a present Example. BRIEF DESCRIPTION OF THE DRAWINGS It is a whole schematic diagram which shows the casting apparatus which manufactures the square hook-shaped melted light metal member which concerns on a present Example. It is a schematic diagram which shows a pair of cooling roll which changed the outer peripheral surface shape (mold part shape). It is a figure which shows the modification of a plate-shaped material, The figure (a) is a schematic diagram which shows a semi-cylindrical plate-shaped material (saddle-shaped material), and the figure (b) is a channel-shaped plate-shaped material. It is a schematic diagram which shows (a bowl-shaped material). It is explanatory drawing which shows a melt | dissolution process, a casting process, a post-processing process, a heating process, and the measurement timing of hardness HVR1-3, The same figure (a) is a case where a hot rolling process is performed as a post-processing process. FIG. 4B shows a case where a cold rolling-heating step is performed as a post-processing step, and FIG. 4C shows a case where a heat treatment step is performed as a post-processing step. In Example 1, it is explanatory drawing which shows the measurement process of the melt | dissolution process, the solidification process, a post-processing process, and a heating process, and hardness HVR1-3, The figure (a) shows a hot rolling process as a post-processing process. FIG. 5B shows the case where a cold rolling-heating step is performed as a post-processing step. It is explanatory drawing which shows each pattern of the behavior of hardness, The figure (a) shows the pattern 1, The figure (b) shows the pattern 2, The figure (c) shows the pattern 3. FIG. It is a photograph which shows the alloy structure (Example 11) before hot rolling. It is a photograph which shows the alloy structure (Example 11) after hot rolling. It is a diagram which shows the relationship between the cooling rate for every Al alloy composition, and tensile strength. It is a SEM photograph of the alloy structure (Example 11) after hot rolling, Comprising: The state in which the precipitate was formed is shown. It is a SEM photograph (1000-times multiplication factor) of the alloy structure of the 1st type Al alloy material (Example 11) before hot rolling. It is a SEM photograph (magnification 5000 times) of the alloy structure of the first type Al alloy material (Example 11) before hot rolling. It is a SEM photograph (magnification 1000 times) of the alloy structure of the 1st type Al alloy material (comparative example 22) before hot rolling. It is a SEM photograph (magnification 5000 times) of the alloy structure of the 1st type Al alloy material (comparative example 22) before hot rolling. It is a component-analysis figure of the crystallization thing of the 1st type Al alloy material (comparative example 22) before hot rolling. It is a TEM photograph of the alloy structure of the first type Al alloy material (Example 11) before hot rolling. FIG. 14 is an analysis diagram of EDX at a point * 1 in FIG. FIG. 14 is an analysis diagram of EDX at a point * 2 in FIG. FIG. 14 is an analysis diagram of EDX at a point * 3 in FIG. FIG. 14 is an analysis diagram of EDX at a point * 4 in FIG. It is a TEM photograph of the alloy structure of the 1st type Al alloy material (Example 11) after hot rolling. FIG. 19 is an analysis diagram of EDX at a point * 1 in FIG. FIG. 19 is an analysis diagram of EDX at a point * 2 in FIG. FIG. 19 is an analysis diagram of EDX at a point * 3 in FIG. FIG. 19 is an analysis diagram of EDX at a point * 4 in FIG. It is the relationship between annealing temperature and residual hardness. It is a microscope picture which shows the metal structure of the plate-shaped raw material which carried out the twin roll casting of the molten metal of Al-25% Si-4% Cu-1% Mg%. It is a microscope picture which shows the metal structure of the plate-shaped raw material which carried out the twin roll casting of the molten metal of Al-25% Si-4% Cu-1% Mg-0.02% P%. It is a microscope picture which shows the metal structure of the plate-shaped raw material which carried out the gravity casting of the molten metal of Al-25% Si-4% Cu-1% Mg%.

Explanation of symbols

A Casting molding equipment M Al alloy molten metal R Thin plate material (plate material)
L Cylindrical member 1 Twin roll caster (Twin roll casting machine)
11, 12 Cooling roll 2 Roll forming machine 21 Forming roller 3 Laser welding machine 4 Cutter

Claims (24)

To a roll casting machine having an annular mold part on the outer peripheral surface side and having at least one cooling roll that rotates, a light metal melt made of a light metal that is one of aluminum (Al), Al alloy, magnesium (Mg), or Mg alloy A material casting step of casting a continuous plate material while rapidly solidifying the light metal melt at the mold part,
A method for producing a melted light metal member, comprising: a shape creating step in which a plate-shaped material that is at least warm due to residual heat during the material casting step is subjected to plastic working to create a desired shape. .   The method for producing a melted light metal member according to claim 1, wherein the roll casting machine is a twin roll casting machine in which the pair of cooling rolls are arranged to face each other in a mold part.   The method for producing a melted light metal member according to claim 1 or 2, wherein at least the outermost surface of the mold part is a high thermal conductive material having a thermal conductivity of 50 W / m · k or more.   The method for producing a melted light metal member according to claim 3, wherein the high thermal conductive material is made of copper (Cu) or a Cu alloy.   5. The method for producing a molten light metal member according to claim 1, wherein in the raw material casting step, a cooling rate of the light metal melt in the mold part is 150 ° C./second or more.   The method for producing a molten light metal member according to any one of claims 1 to 5, wherein the mold part is water-cooled from an inner peripheral surface side of the cooling roll. The mold part consists of a flat annular band,
The method for producing a melted light metal member according to claim 1, wherein the plate material is a flat plate material having a substantially constant plate thickness.   The method for producing a molten light metal member according to claim 1, wherein the mold part is formed of an annular groove having a concave cross-sectional shape in the width direction of the cooling roll.   The method for manufacturing a melted light metal member according to claim 8, wherein the plate-shaped material is a bowl-shaped material.   The method for producing a melted light metal member according to claim 8, wherein the plate-shaped material is an uneven-thick material having an uneven cross-sectional shape in the width direction.   The manufacturing method of the molten light metal member of Claim 1 whose temperature of the plate-shaped raw material at the time of carrying out plastic working at the said shape creation process is 200 degreeC or more.   Furthermore, the manufacturing method of the molten light metal member of Claim 1 or 11 provided with the heating process which heats the said plate-shaped raw material and makes this plate-shaped raw material in the said shape creation process into a warm state or a hot state. .   The method for producing a melted light metal member according to claim 1 or 12, wherein the plastic working is at least one of roll forming, pressing, punching, burring, and hemming.   Furthermore, the manufacturing method of the melted light metal member of Claim 1 or 13 provided with the heat processing process which heat-processes the said raw material.   The method for producing a melted light metal member according to claim 1, wherein the light metal is a general-purpose Al alloy. When the light metal is 100% as a whole,
Iron (Fe) as the first component element: 0.8 to 5%,
While containing titanium (Ti) as the second component element: 0.15 to 1%,
One kind selected from the third component element group consisting of zirconium (Zr), niobium (Nb), hafnium (Hf), scandium (Sc), and yttrium (Y), and each content is 0.05-2% The total amount (X) of the third component element is more than Ti and less than Fe (Fe%>X%> Ti%),
The method for producing a melted light metal member according to claim 1, wherein the balance is a first type Al alloy comprising Al and inevitable impurities and / or modifying elements. The raw material casting step is a melting step in which the light metal is melted by melting the light metal at a temperature 20 ° C. or higher than the liquidus temperature determined from the composition;
2. A solidification step in which the light metal melt is rapidly solidified at a cooling rate of 150 ° C./second or more and less than 10000 ° C./second to a temperature at least 10 ° C. lower than the solidus temperature determined from the composition in the mold part. Or the manufacturing method of the melted light metal member of 16. When the light metal is 100% as a whole,
Silicon (Si): 17 to 43%;
Cu: 0.2 to 7%,
Magnesium (Mg): 0.05-4%
The method for producing a melted light metal member according to claim 1, wherein the balance is a second-type Al alloy comprising Al and inevitable impurities and / or modifying elements.   The method for producing a melted light metal member according to claim 1, wherein the shape creation step is a roll forming step in which the plastic forming is roll forming.   Furthermore, the manufacturing method of the melted light metal member in any one of Claims 1-19 provided with the cooling process which cools the said plate-shaped raw material after peeling from the said cooling roll to predetermined temperature with a cooling medium.   A melted light metal member produced by the method according to claim 1. Manufactured by the method of claim 16,
The plate material has a metal structure having an α phase composed of an Al matrix and a layered phase surrounding the α phase composed of a eutectic structure of the Al matrix and an Al—Fe-based compound,
The Al base is composed of an Al supersaturated solid solution in which the second component element and the third component element are dissolved in Al and / or Al.
A melted light metal member characterized in that an area ratio occupied by a crystallized material having a particle size of 5 μm or more composed of an intermetallic compound of Al and the second component element and / or the third component element is less than 5%. The melted light metal member according to claim 22, wherein a particle size of a precipitate made of the intermetallic compound dispersed in the Al base is 2 to 500 nm.
. Manufactured by the method of claim 18,
The plate-like material has a metal structure composed of primary Si particles having an average particle diameter in a circle equivalent diameter of 5 to 50 μm and a matrix holding the dispersed primary crystal Si particles in at least a surface layer portion. A melted light metal member characterized by excellent wear characteristics.