WO1990002008A1 - Process and device for producing metallic laminated composite materials and their use - Google Patents

Abstract

In a process for producing metallic composite materials, at least one solid web-like metallic component (6) is united with a second metallic component (2) ejected in a molten state from a slot nozzle (4) before the roll gap between two cooling rolls (5) and the united metallic components are led through the roll gap. It is proposed to thermally insulate at first the web-like metallic components in relation to the adjacent cooling roll, in an area where they contact the second fluid metallic component ejected from the slot nozzle, thus maintaining the second metallic component in the molten state at least in part of this area of the contact surface with the web-like metallic components. Afterwards, however, the first metallic component is cooled down by thermal treatment with the cooling roll in such a way that the temperature of the second metallic component has fallen below its solidus temperature over its whole cross-section before it comes out of the roll gap, the thickness of the united metallic components being reduced when they are led through the roll gap.

Description

 Method and device for the production of metallic layer composite materials and their use

Metallic layered composite materials, such as those used for composite bearings, are produced by different processes depending on the material combination and the geometrical dimensions. These are, for example, pouring-on processes, such as according to the published German patent application Seh 11 908 VI / 31c, sintering, electrolysis or ionization processes, which can also be used in combination with one another. These methods are complex and can only be used with certain material combinations. For the production of layered metal composites in which at least one of the metal components is pure aluminum or an aluminum alloy, the most common method is roll-cladding, such as one described in DE-AS 12 03 086.

In the roll plating process, two sheet-like solid metal components are combined with one another by passing through the roll gap of a pair of rolls that reduces the thickness of the entirety of the two metal components. In order to achieve good adhesion of the two web-shaped metal components to one another, the surfaces of the two metal webs which come into contact with one another must be carefully prepared beforehand and freed from disruptive influences, such as scale, oxide layers, grease and other contaminants. In addition, roll cladding requires good process control in order to achieve optimum forming conditions, the forming having to be controlled in such a way that the low-melting components of the alloy do not exceed their solidus point due to the forming heat.

The high degrees of deformation required in roll cladding often lead to edge cracks that limit the useful width of the composite material. Subsequent annealing processes, in combination with further forming, lead to segregation processes and a conglomeration of the low-melting phase, as well as to a linear structure.

US Pat. No. 4,303,741, US Pat. No. 4,224,978 and FR Pat. No. 1,364,758 describe devices and methods for producing metallic layer coatings. Bundled materials in which a metal component emerges in a molten state from a slot nozzle and is joined behind the slot nozzle with one or two metal tracks and in which the combined metal components are passed through the nip of a pair of cooling rollers. Since the metal component emerging from the slot nozzle leaves the roll gap at least in the melt, there is no rolling effect with the associated positive effects on the microstructure.

The object on which the invention is based was therefore to produce metallic layer composite materials by a new process which eliminates the disadvantages of known processes and improves the structure of the product. In particular, the melting of the metal component emerging from the slot nozzle onto the metal tracks is to be improved, but at the same time the desired structural change is to be obtained by rolling.

The process according to the invention for the production of metallic layered composite materials, in which at least one solid sheet-like metal component is combined with a second metal component which emerges in a molten form from a slot nozzle in front of the roll gap of a pair of cooling rolls and the combined metal components are passed through the roll gap, is characterized in that the web-shaped metal components are first kept thermally insulated from the adjacent cooling roller in an area in contact with the molten second metal component emerging from the slot nozzle, and the second metal component is thus at least in part of this area at the contact surface with the web-shaped metal component holds molten, but then cools by heat dissipation with the help of the adjacent cooling roll in such a way that the second metal component as a whole has its soliduste perature before entering the roll gap has passed, and reduced the thickness of the combined metal components when passing through the roll gap.

This method has the advantage that the melt of the second metal component emerging from the slot nozzle is not cooled or not cooled as long as is necessary for sufficient melting to the surfaces of the sheet-shaped metal components, which is in the heat-iced area between the outlet of the slot nozzle and the roll gap he follows. After leaving this heat-insulated area, the sheet-like metal components with the melted-on second metal component come into thermal contact with the adjacent cooling roll, as a result of which the second metal component solidifies rapidly, so that it is completely solidified before the combined metal components emerge from the roll gap , wherein its temperature is above its recrystallization temperature, if necessary, in order to achieve the desired structure.

It is expedient for the sheet-like metal components to be kept thermally insulated in a region which is variable with respect to the length in the direction from the slot nozzle to the roll gap, i.e. can change the length of the heat-insulated area in the direction between the slot nozzle and the roll gap. In this way you can adapt the process to different materials and achieve different structures. If two solid sheet-like metal components are fed to the process on both sides of the second metal component emerging moltenly from the slot nozzle, it is possible to obtain different structures on both sides of the second metal component by means of independently variable adjustment of the area which is kept thermally insulated, above and below it is desired for certain properties of the layered composite material.

It is expedient to extend the area of thermal insulation between the respective cooling roller and the adjacent sheet-like metal component in the opposite direction to that of the sheet-like metal component, preferably to such an extent that the sheet-like metal component does not come into contact at all between the slot nozzle and the adjacent cooling roller comes with the surface of the chill roll. The web-shaped metal component is then only cooled on the route between the exit of the slot nozzle and the roll gap after it has left the heat insulation zone by the adjacent cooling roll.

According to a further preferred embodiment of the method according to the invention, the sheet-shaped metal components are heated before entering between the slot nozzle and the adjacent cooling roller in order to further improve the melting of the second metal component. The warming Mung can be done for example by radiant heaters, induction heating or the like.

At the same time, the method according to the invention overcomes the disadvantages of known methods described at the outset and reduces the number of work steps, since a layered composite material is obtained which has at least approximately the desired final dimensions. In addition, at most one surface, namely that of the sheet-like metal component, must be pretreated and freed from disruptive influences. In certain cases, such pretreatment is generally unnecessary.

The method according to the invention also improves the microstructure formation by reducing the forming and annealing processes, since subsequent annealing processes are generally superfluous, and allows the cooling conditions to be optimized. Finally, in the method according to the invention, the reject is greatly reduced, since, in contrast to the roll cladding method, there are generally no edge cracks and, as a result, the useful width of the layered composite material is not or is only slightly restricted.

In the method according to the invention, for example, a single solid sheet-like metal component can be used and combined with the second metal component. Layered composite materials of this type are used particularly advantageously for the subsequent combination with support bodies for composite bearings, i.e. to form the bearing material and the metallic interlayer in composite bearings.

However, two solid sheet-shaped metal components, which can be the same or different in their metallic composition, can also be used in the present process, the molten metal component being introduced between these two metal sheets and being combined with both at the same time. In this case, a sandwich composite of sandwich-like construction is obtained.

Regardless of whether one or two metal webs are fed, the feed is expediently such that the metal webs enter the roll gap essentially horizontally and the second molten metal component nente also emerges essentially horizontally from the slot nozzle. When using two metal webs and creating a sandwich-like structure, one metal web is expediently fed from above and one from below to the slot nozzle.

In the method according to the invention, in contrast to roll plating, a metal component is supplied in molten form. This emerges from a slot nozzle extending over the width of at least one sheet-shaped metal component and is combined with the solid sheet-shaped metal components essentially immediately behind the slot nozzle and before it emerges from the roll gap.

The materials are preferably selected so that the sheet-like metal components melt on their surfaces when they come into contact with the second molten metal component, while immediately afterwards by means of heat dissipation with the aid of the cooling rollers, the melted-on area and usually also the adjacent area of the molten metal component - Solidify again to form a homogeneous connection zone with the second metal component.

Since the sheet-like solid metal components must be passed through the roll gap in addition to the second metal component emerging from the slot die, i.e. between the slot nozzle and one of the heat-insulating bodies or one of the rollers of the pair of rollers, the slot nozzle must be sealed along one of its mouth sides along the slot length against one of the two rollers of the pair of rollers or against one of the fixed metal tracks, while the other Mouth side along the length of the slot must be sealed against the metal web passed between it and the other roller of the pair of rollers.

Sealing is generally not problematic and can, for example, take place automatically through a solidified portion of the second metal component that has penetrated into the gap to be sealed.

The size of the roll gap exit, which is designated h in the drawing, is expediently set in the process according to the invention in such a way that the layered composite material leaving the roll gap has approximately the desired final thickness after cooling. In this process, depending on the material, dynamic recrystallization can take place, producing the desired structure. According to the above, it is necessary for the second component to be completely solidified when it enters the roll gap, ie to have fallen below its solidus temperature and to undergo the necessary shaping. On the other hand, when passing through the roll gap, the heat originating from the melting process is used, so that an additional heating process, such as is required for roll cladding according to DE-AS 1203086, becomes superfluous. r

In order to achieve a homogeneous and uniform union of the two metal components, it is expedient to feed the sheet-like solid metal components under tension to the point of union with the second metal component and thus advantageously also to lead them through the roll gap under tension.

The width of the slot nozzle, the size of the roll gap, the diameter of the rolls and the resulting distance of the slot nozzle from the roll gap depends in the method according to the invention on the materials to be used for the layered composite material and the desired final thickness of the layered composite material. Expediently, however, the slot nozzle and the roll gap are set so that the Stichabπah e

1 to 30%, preferably 5 to 15%, the thickness of the layered composite material at the point of falling below the solidus temperature of the second metal component over essentially its entire cross section and h, the thickness of the layered composite material when it emerges from the roll gap. With such a setting of the slot nozzle and roll gap, a particularly favorable combination of the two metal components is obtained, producing a layered composite material close to the final dimensions. Depending on the materials used, it may be expedient for the surface of the solid sheet-like metal components which is combined with the second metal component to be supplied with such influences before being fed to the point which forms the seal between the slot nozzle and the first sheet-like metal component free that would interfere with the union of the two metal components. Such influences include scale, oxide layers, grease and other contaminants, which are removed by descaling, removal of oxide layers, degreasing (washing or cleaning).

The device according to the invention for producing metallic layered composite materials with a pair of cooling rolls forming a nip, with a container for molten metal arranged in front of the nip with a slot nozzle directed towards the nip and with devices for introducing at least one metal web between the slot nozzle and at least one of the Cooling rolls and the subsequent guiding of this metal web through the roll nip is characterized in that the devices for guiding the metal web bring it into cooling contact with the adjacent cooling roll in a partial region of the distance between the outlet of the slot die and the outlet of the roll nip up to the latter , while a heat-insulating body is arranged in the remaining part of this section adjoining the slot nozzle between the metal web and the adjacent cooling roll.

The slot nozzle is expediently directed onto the roll gap in such a way that the outlet of the slot nozzle runs essentially horizontally and the molten second metal component is guided substantially horizontally further in the direction of the roll gap and in this.

The heat-insulating body can have different shapes. However, it expediently has the shape of a crescent-shaped guide element. The material of the heat-insulating body with poor thermal conductivity depends on the materials to be processed in each case and other process conditions. It is expedient if the heat-insulating body has a surface on which the metal web running on it is sufficient Has gliding or rolling elements. If necessary, the heat-insulating material can be provided with a surface which improves the slidability of the metal sheet.

As mentioned above, it is expedient to be able to change the length of the heat insulation zone between the outlet of the slot nozzle and the roll gap in order to be able to adapt the device to different materials and different structural requirements. For this purpose, the heat-insulating body can be pivoted or displaced in such a way that the length of the heat-insulating region between the slot nozzle and the roll gap is variable. Instead, the heat-insulating body can also be fixed and the slot nozzle can be moved back and forth in the direction of the roll gap. The latter is particularly expedient if two metal tracks are to be fed to the device above and below the slot nozzle.

As has already been explained above in connection with the method according to the invention, it is expedient to extend the heat-insulating body in the opposite direction to the metal webs in such a way that the metal webs do not exist at all in the area between the slot die and the roll gap before the start of the cooling zone come into contact with the adjacent cooling roller.

A heating device for heating the metal web is preferably arranged between the slot nozzle and the adjacent heat-insulating body before the metal web enters. This heating device can be, for example, a heat radiator, an induction heater or the like.

Furthermore, for the production of sandwich-like layered composite materials, each with a metal sheet on both sides of the second metal component, it is expedient that each of the two cooling rollers is assigned a heat-insulating body and that these two heat-insulating bodies can be pivoted or displaced independently of one another. so that you can separately change the length and length of the upper and lower heat insulation areas between the slot nozzle and the roll gap, so that layered composite materials with different structures can be obtained on both sides of the second metal component. Show in the drawing

FIG. 1 shows in schematic form an installation for carrying out the method in one embodiment of the invention, partly in section,

FIG. 2 shows an enlarged representation of the roll gap area in accordance with the first embodiment of the invention explained in FIG. 1,

Figure 3 is an enlarged view of the roll gap area corresponding to Figure 2 for a second embodiment of the invention and

Figure 4 is an enlarged view of the roll gap area corresponding to Figures 2 and 3, but for yet another embodiment of the invention.

The plant shown in Figure 1 of the drawings for performing the method according to the invention has a pair of rollers 5 with an upper roller 5a and a lower roller 5b. The melt 2 of the second metal component is located in a holding furnace 1. The trough 3, which ends as a slot nozzle 4, adjoins the holding furnace 1. The holding furnace 1, the trough 3 and the slot nozzle 4 are shown in vertical section. The trough 3 still contains the second metal component in the molten state 2a, while the same component is already in the solid state 2b when it passes through the roll gap.

From the reel 7 arranged in the pit 8, the web-shaped metal component in the form of a strip 6 is passed in the direction of the arrow 12 between the roller 5b and the slot nozzle 4 and then through the roll gap. At the cleaning station 10, the contact surface 9 of the belt 6 is freed from interfering influences, such as degreased, descaled or freed from oxide layers. A heat-insulating body 13 in the form of a blade is arranged between the belt 6 and the roller 5b, the tip of which body extends into the area between the outlet of the slot nozzle 4 uπd the roll gap is enough. A heating device 14 is provided opposite the heat-insulating body 13 on the other side of the belt 6. The metallic layered composite material leaving the process at the end is designated 11 in the drawing.

In Figures 2 to 4, the same parts as in Figure 1 to the same reference numerals. The embodiment shown in FIG. 2 corresponds to that of FIG. 1, in which only one metal sheet 6 is fed to the device, and therefore only one heat-insulating body 13 and one heating device 14 are provided. The shovel-shaped heat-insulating body 13 is solid in this case, i.e. arranged immovable and unmovable. The thicknesses of the layer composite material on the one hand at the point where the solidus temperature of the second metal component (h) falls below and on the other hand at the exit from the roll gap S (h,) are given in FIG

The embodiment according to FIG. 3 differs from that according to FIG. 2 in that a sandwich structure of the layered composite material is obtained, since two metal tracks 6 and 6 'are fed in, so that in this case two heat-insulating bodies 13 and 13' and two heating devices 14 and 14 'are provided.

Finally, the embodiment according to FIG. 4 differs from that according to FIG. 2 in that the heat-insulating body 13 is designed to be pivotable, which is indicated by several positions at 13c. Due to the pivotability, the heat-insulating body 13 with the extension 13b can be immersed to different extents in the area between the outlet of the slot nozzle and the roll gap, so that the heat-insulating zone 13a can be varied in this area.

example

With reference to the drawing, the method according to the invention will now be explained on the basis of a special exemplary embodiment which is suitable for producing a layered composite material for combining with support bodies for composite bearings. As a fixed strip of the first metal component, an aluminum strip made of pure aluminum with a purity of 99.5% is passed between the slot nozzle and heat-insulating body 13 into the roll gap. The liquid second metal component that emerges from the slot nozzle 4 has the composition AlSnδCulNil. The melt of this second metal component has a temperature of about 750 ° C. The first metal component pretreated in the cleaning station 10 in the form of the pure aluminum strip 6 has room temperature.

The bandwidth of the pure aluminum strip 6 is 300 mm, the width of the slot nozzle is also 300 mm, the roller diameter is approximately 500 mm, the thickness h 9.4 mm and the thickness h, 8 mm.

According to this example, a layered composite material is produced in a continuous process, which is suitable as a bearing material with a metallic intermediate layer for combination with the support body for composite bearings.

Claims

Patent claims 1. A process for the production of metallic layered composite materials, in which at least one solid sheet-like metal component is combined with a second metal component which emerges in a molten form from a slot nozzle in front of the roll gap of a pair of cooling rolls and the united metal components are passed through the roll gap, characterized in that the web-shaped metal components initially in a region of contact with the molten second metal component emerging from the slot nozzle keeps heat-insulated from the adjacent cooling roll and in this way keeps the second metal component molten at least in part of this area at the contact surface with the web-shaped metal component , but then cools by heat treatment with the help of the adjacent cooling roll in such a way that the second metal component below its solidus temperature over its entire cross-section before it emerges (S) from the roll gap has reached, and reduces the thickness of the combined metal components by passing them through the nip. 2. The method according to claim 1, characterized in that one keeps the bahn¬ shaped metal components in a variable with respect to the length in the direction from the slot nozzle to the roll gap against the adjacent cooling roll insulated. 3. The method according to any one of claims 1 to 2, characterized in that the sheet-shaped metal components are fed under tension to the point of union with the second metal component. 4. The method according to any one of claims 1 to 3, characterized in that the slot nozzle and the outlet of the roll gap (S) are adjusted so that the stitch decrease ^h x ^" 100% 1 to 30%, preferably 5 to 15%, where h is the thickness of the layered composite material at the point where the solidus temperature of the second metal component falls below its entire cross section and h is the thickness of the layered composite material when it emerges from the roll gap. 5. The method according to any one of claims 1 to 4, characterized in that the sheet-shaped metal components on its side facing the second metal component are freed from the interfering influences before being combined with the latter. 6. The method according to any one of claims 1 to 5, characterized in that the sheet-like metal components are heated before contact with the second molten metal component. 7. The method according to any one of claims 1 to 6, characterized in that one melts the sheet-like metal components on contact with the second molten metal component on their surfaces and immediately thereafter by heat dissipation with the help of the cooling rollers, the melted areas to form a homogeneous Allows the connection zone to solidify again with the second metal component. 8. Device for the production of metallic layered composite materials with a pair of cooling rolls forming a nip, with a container for molten metal arranged in front of the nip with a slot nozzle directed towards the nip and with devices for introducing at least one metal web between the slot nozzle and at least one one of the cooling rolls and also for guiding this metal web through the roll gap, characterized in that the devices for guiding the metal web (6, 6 ') cover this in a partial region of the path between the outlet of the slot nozzle (4) and the outlet of the Bring the nip (S) up to the latter into cooling contact with the adjacent cooling roller (5), while in the remaining part of this section adjoining the slot nozzle (4), this occurs between the metal web (6, 6 ') and the adjacent cooling roller (5) heat-insulating body (13, 13 ') is arranged. 9. The device according to claim 8, characterized in that the heat-insulating body (13, 13 ') has the shape of a sickle-shaped guide element. 10. Apparatus according to claim 8 or 9, characterized in that the heat-insulating body (13, 13 ') is arranged such that it can be pivoted or moved such that the length of the heat-insulating region between the slot nozzle (4) and the roll gap is variable. 11. The device according to claim 8 or 9, characterized in that the heat insulating body (13, 13 ') is fixed and the slot nozzle (4) can be moved back and forth in the direction of the roll gap. 12. Device according to one of claims 8 to 11, characterized in that before the entry of the metal tracks (6, 6 ") between the slot nozzle (4) and the heat-insulating bodies (13, 13 ¹ ) heating devices (14, 14 ¹ ) Heating the metal tracks is arranged. 13. Device according to one of claims 8 to 12, characterized in that each of the two cooling rollers (5a, 5b) is associated with a heat-insulating body (13, 13 ^r ) which are pivotable or displaceable independently of one another. 14. Device according to one of claims 8 to 13, characterized in that the heat-insulating body (13, 13 ') outside the area (13a) between the outlet of the slot nozzle (4) and the roll gap one zblatt Has extension (13b), which prevents contact between the metal web (6, 6 ") and the cooling roller (5). 15. Use of a layered composite material produced by the method according to one of claims 1 to 7 for combination with support bodies for plain bearing elements made of layered composite materials.