CN115502543A - Method and device for multi-filament cyclic gradient stir friction additive manufacturing - Google Patents

Abstract

The invention discloses a method and device for the manufacture of multi-filament circular gradient stir friction additives. S1. Determining the ratio of the filaments: calculating the proportion required for each layer of the gradient material to be prepared, and determining the filaments of different materials on both sides of the substrate The use ratio of A and wire B; S2, setting wire feeding rate: adjust the wire feeding speed on both sides of the substrate, and feed wire A and wire B into both sides of the stirring needle respectively; S3, friction additive: friction stirring Wire A, wire B and the surface of the substrate, so that the thermoplastic state of wire A and wire B is combined with the surface of the substrate to form the first layer of material; S4, gradient material preparation: repeat S3 until the deposition of the gradient material is completed. The invention can realize stable material feeding in the friction additive process, the mold can be used repeatedly, the economic benefit is strong, the materials can be prepared with many options, the application range is large, the interface of the prepared gradient material is tightly bonded, and the working efficiency of the gradient additive is high.

Description

Method and device for multi-filament cyclic gradient stir friction additive manufacturing

technical field

The invention relates to the technical field of additive manufacturing, in particular to a method and device for multi-filament circulation gradient stir friction additive manufacturing.

Background technique

Gradient functional material is a composite material that exhibits a certain performance in a specific direction that changes continuously. Two or more materials with different properties can be selected according to needs, and the material properties presented by the composite can be changed. It has high temperature resistance, wear resistance, Corrosion resistance and the ability to ease thermal stress in environments with huge temperature differences are often used in aerospace, energy development and other fields.

The traditional preparation methods of gradient functional materials include: plasma spraying method, self-propagating combustion high-temperature synthesis method, vapor phase deposition method, etc., but there are cumbersome steps in the preparation process, high production cost, low energy utilization rate, large pollution, and the size of the prepared material At present, additive manufacturing is usually used to prepare gradient materials, but powders are generally used as raw materials, resulting in defects such as pores and poor interface bonding in the prepared materials, while multi-filament additive manufacturing can be bottom-up The unique layer-by-layer processing has the characteristics of high material utilization rate, less internal defects, small stress and good performance.

However, the existing multi-filament additive manufacturing needs to replace the friction stir tool after adding material for a period of time, resulting in intermittent additive process that cannot guarantee the stability of the performance of the gradient material, and the continuously added wire is in the rotation process of the shaft shoulder and the stirring needle It is easy to break in the middle, resulting in unstable feeding, such as a granular friction stir additive manufacturing device and method in the patent No. CN113118612B, because the wire is easy to break during the rotation of the stirring needle, by actively cutting the wire, the granular The filament material is fed into the stirring needle for friction additives. Compared with the powder additive material, it can reduce the contact area with the air and reduce the internal defects of the gradient material, but the granular wire material is difficult to obtain during use. The high-speed rotating stirring needle will also have the disadvantages of unstable feeding and loose interface bonding. Therefore, there is an urgent need for a method and device for multi-filament cyclic gradient stir friction additive manufacturing to solve the above-mentioned problems.

Contents of the invention

The purpose of the present invention is to provide a method and device for multi-filament cyclic gradient stir friction additive manufacturing to solve the above-mentioned problems in the prior art, to realize stable feeding during the friction additive process, and to reusable molds with strong economic benefits. There are many choices of materials and a wide range of applications. The interface of the prepared gradient material is closely combined, and the work efficiency of gradient additive is high.

In order to achieve the above object, the present invention provides the following scheme: the present invention provides a method for multi-filament cyclic gradient stir friction additive manufacturing, comprising the following steps,

S1. Determining the ratio of wire materials: calculate the required proportion of each layer of the gradient material to be prepared, and determine the use ratio of wire A and wire B of different materials on both sides of the substrate;

S2. Setting the wire feeding rate: adjust the wire feeding speed on both sides of the substrate, and feed the wire A and the wire B into both sides of the stirring needle respectively;

S3. Friction additive: Stir and rub the wire A, the wire B, and the surface of the substrate, so that the wire A and the wire B in a thermoplastic state combine with the surface of the substrate to form a first layer Material;

S4. Gradient material preparation: S3 is repeated until the deposition of the gradient material is completed.

In a further optimized solution, in step S3, the stirring pin is rotated at a high speed, and the wire A and the wire B are transported to the surface of the substrate through the stirring pin.

In a further optimization scheme, in step S4, the stirring needle extends into the thermoplastic filament A and the filament B, and the substrate, the filament A and the filament B are rotated by the stirring needle The first layer of material is formed.

In a further optimized solution, in step S4, the length of the bottom stirring needle fixed to the bottom of the stirring needle protruding into the second layer of material or the multilayer material is greater than the thickness of the single layer of material.

To further optimize the solution, in step S1, wires of different materials are determined according to the composition ratio required for each layer of the gradient material, and the wire feeding rate of the wires is determined in combination with the rotation speed of the stirring pin.

To further optimize the scheme, in step S2, the wire feeding rate of the conveying wire is adjusted to be consistent with the wire feeding rate calculated in step S, and the wire A and the wire B are passed through both sides of the stirring needle respectively. Insert the stirring needle.

A device for multi-filament cyclic gradient stir friction additive manufacturing, including a substrate,

Two wire feeding mechanisms are arranged on both sides of the base plate, the wire feeding mechanism has a discharge end and a feed end, and the two wires move towards each other through the discharge ends of the two wire feeding mechanisms coaxially;

The wire guide mechanism is arranged above the base plate. The wire guide mechanism is provided with two feeding ports corresponding to the discharge ends of the two wire feeding mechanisms. The wire material extends into the guide wire through the feeding ports. inside the silk mechanism;

The stirring needle is arranged in the wire guide mechanism, and the side wall surface of the stirring needle is provided with a feed tank, and the feed tank is used to derive the gradient material for additive manufacturing;

The bottom end of the stirring needle protrudes from the wire guide mechanism and is in sliding contact with the top of the substrate, and the stirring needle is rotatably connected to the wire guide mechanism.

In a further optimization scheme, the wire feeding mechanism includes two wire feeding wheels arranged on one side of the substrate, the adjacent sides of the two wire feeding wheels rotate in the same direction, and the two wire feeding wheels cooperate to form a wire feeding channel, And the two wire feeding passages located on both sides of the base plate are arranged on the same axis, and the two wire materials move towards each other through the two wire feeding passages respectively, and the material inlet and the outlet of the wire feeding passage end-corresponding settings.

In a further optimization scheme, the wire guide mechanism is a stationary shoulder arranged above the base plate, the two feed ports are oppositely set on the side wall of the stationary shoulder, and the stirring needle is arranged on the stationary shoulder inside, and the feeding chute is set correspondingly to the feeding port, one end of the wire passes through the feeding port and extends into the feeding chute, and the stirring needle is rotatably connected with the stationary shoulder .

In a further optimization solution, the feeding trough is a threaded groove opened counterclockwise or clockwise from top to bottom, the bottom end of the feeding trough communicates with the outside of the stirring needle, and the stirring needle is along the The feed chute rotates in the opposite direction.

The invention discloses the following technical effects:

The present invention adjusts the conveying speed of the wire through the wire feeding mechanism, and sets the wire guide mechanism to directly pass the wire into the guide wire mechanism, so as to ensure the stable conveying of the wire and the stable connection with the feeding trough set on the stirring needle, improving the Feeding stability, and by rotating the stirring needle, the filament can reach a thermoplastic state by using frictional heat, flow to the surface of the substrate through the feeding tank, and use the stirring needle to rotate and mix the filament and the substrate, thereby preparing the first layer of material with small interface defects , and then repeat the operation to superimpose the second layer of material on the first layer of material to prepare a multi-layer gradient material. Not only the interface of the prepared gradient material is tightly bonded, the work efficiency of the gradient additive is high, and the filaments on both sides of the substrate can be Selectively add wire A and wire B to improve the selectivity of preparing gradient materials, make it applicable to a wide range, not limit the difference in melting point of the two constituent wires, increase the types of materials that can be processed in gradients, and the preparation process No additional heat source is needed for heating, and only the driving device is set to drive the stirring needle to rotate and friction, which simplifies the additive manufacturing process, and the stirring needle can be reused, saving the use cost.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without paying creative labor.

Fig. 1 is the structural representation of overall device;

Fig. 2 is the structural representation of stirring pin;

Fig. 3 is the structural representation of bottom stirring needle;

Fig. 4 is a structural sectional view of a static shoulder;

Fig. 5 is the structural schematic diagram of gradient material prepared by stirring pin;

Fig. 6 is the schematic diagram of multi-layer wire feeding rate;

Fig. 7 is a schematic diagram of the positional relationship between the stirring needle and the first layer of material and the second layer of material;

Among them, 1. Stirring needle; 101. Feed trough A; 102. Feed trough B; 103. Bottom stirring needle; 2. Stationary shoulder; 201. Feed port A; 202. Feed port B; 3. Silk Material A; 4. Wire material B; 5. Substrate; 6. First layer material; 7. Second layer material; 8. Wire feed wheel; 9. Gradient material.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Referring to Figures 1-7, the present invention provides a method for multi-filament cyclic gradient stir friction additive manufacturing, which includes the following steps,

S1. Determining the ratio of the wire material: calculate the required proportion of each layer of the gradient material 9 to be prepared, and determine the use ratio of the wire A3 and the wire B4 of different materials on both sides of the substrate 5;

S2. Setting the wire feeding rate: adjust the wire feeding speed on both sides of the base plate 5, and feed the wire material A3 and the wire material B4 into both sides of the stirring needle 1 respectively;

S3. Friction additive: stir and rub the surface of the wire A3, the wire B4 and the substrate 5, so that the thermoplastic state of the wire A3 and B4 is combined with the surface of the substrate 5 to form the first layer of material 6;

S4. Preparation of the gradient material 9: repeating S3 until the deposition of the gradient material 9 is completed.

The present invention determines the preparation composition of the gradient material 9 in advance, determines the material of the wire material, and formulates the delivery rate of the wire material, so as to ensure the stable feeding of the additive manufacturing process through the friction of the stirring needle 1, and effectively improve the selectivity of the prepared material , Enlarging its scope of application, fully mixing the wire material A3 and the wire material B4 through the rotation of the stirring needle 1, so that the interface of the prepared gradient material is closely combined, and the working efficiency of the gradient additive material is high.

To further optimize the solution, in step S3, the stirring needle 1 is rotated at a high speed, and the wire A3 and the wire B4 are transported to the surface of the substrate 5 through the stirring needle 1 .

To further optimize the solution, in step S3, the stirring needle 1 extends into the thermoplastic wire A3 and wire B4, and the substrate 5, the wire A3 and the wire B4 are rotated by the stirring needle 1 to form the first layer of material 6.

In a further optimized solution, in step S4, the bottom stirring needle 103 fixed to the bottom of the stirring needle 1 extends into the second layer of material 7 or the length of the multi-layer material is greater than the thickness of the single-layer material layer.

To further optimize the scheme, in step S1, wires of different materials are determined according to the required composition ratio of each layer of the gradient material 9, and the wire feeding rate of the wires is determined in combination with the rotation speed of the stirring needle 1.

To further optimize the scheme, in step S2, the wire feeding rate of the conveying wire is adjusted to be consistent with the wire feeding rate calculated in step S1, and the wire A3 and the wire B4 are respectively passed into the stirring needle 1 through both sides of the stirring needle 1.

Referring to accompanying drawing 6, according to the specific composition and ratio required for each layer of the gradient material 9 to be prepared, determine the wire material and the wire feeding rate that each layer needs to participate in the preparation, and the wire material is continuous and the size is known. The wire feeding rate required for each layer needs to be based on the material ratio required for each layer. The formula ω=V _{A wire} /V _{B wire} and the formula V _{A wire} *S _{A wire} +V _{B wire} *S _{B wire} =S _{single layer} * In order to ensure that the output volume of each layer is the same when the travel speed is constant, and thus ensure that the sum of the wire feeds used _in each layer is as consistent as possible, while maintaining stable feeding, it can effectively reduce the preparation of gradient materials. 9 The interface defects can enhance the strength of the additive structure.

In one embodiment of the present invention, the bottom stirring needle 103 is preferably but not limited to a triangular pyramid structure, fully stirs the two kinds of wire materials A3 and B4, expands the stirring area to ensure normal mixing and flow between materials during the preparation process, and stirs at the bottom The structural length of the needles 103 is greater than the individual layer thickness of the production material layer.

After the first layer of material 6 is prepared, lift the welding tool to the thickness of a single layer at the end of the first layer of material 6, and stay there for a period of time to adjust the feeding rate of each wire material set in the next layer. wire speed. Then the welding tool moves, and the material moves downward continuously and reaches the surface of the first layer of material 6. On the one hand, under the agitation of the bottom stirring needle 103, the two kinds of wire materials are stirred and mixed evenly, on the other hand due to the stirring of the stirring needle 103 Insert the first layer of material 6 to a certain depth, so as to stir the interface between the first layer of material 6 and the second layer of material 7, so that the materials on both sides of the interface flow into each other so as to achieve the state of mutual bonding between the two layers. After the preparation of the second layer of material 7 is completed, the welding tool is lifted to a fixed height and circulated to construct a multi-layer gradient material 9 .

In one embodiment of the present invention, when the heat generated by the friction process of the stirring pin 1 is large or the prepared gradient material 9 is easily oxidized, gas protection measures, such as nitrogen protection, argon and other inert gas protection, can be selected.

A device for multi-filament cyclic gradient stir friction additive manufacturing, including a substrate 5,

Two wire feeding mechanisms are arranged on both sides of the base plate 5. The wire feeding mechanism has a discharge end and a feed end, and the two wires move towards each other through the discharge ends of the two wire feeding mechanisms coaxially;

The wire guide mechanism is arranged above the base plate 5. The wire guide mechanism is provided with two feed ports corresponding to the discharge ends of the two wire feed mechanisms, and the wire material is inserted into the wire guide mechanism through the feed ports;

The stirring needle 1 is arranged in the guide wire mechanism, and the side wall surface of the stirring needle 1 is provided with a feeding groove, and the feeding groove is used to derive the gradient material 9 for additive manufacturing;

The bottom end of the stirring needle 1 protrudes from the wire guiding mechanism and slides in contact with the top of the base plate 5, and the stirring needle 1 is rotationally connected with the wire guiding mechanism.

The present invention adjusts the wire material conveying speed through the wire feeding mechanism, and sets the wire guide mechanism to directly pass the wire material into the wire guide mechanism, so as to ensure the stable conveying of the wire material and the stable connection with the feeding trough set on the stirring needle 1, By rotating the stirring needle 1, the filament material reaches a thermoplastic state by using frictional heat, flows to the surface of the substrate 5 through the feeding trough, and uses the stirring needle 1 to rotate and mix the filament material and the substrate 5, thereby preparing the first layer of material 6 with small interface defects , and then repeat the operation to superimpose the second layer of material 7 on the first layer of material 6, thereby preparing a multi-layer gradient material 9, not only the interface of the prepared gradient material is tightly bonded, but also the working efficiency of the gradient additive is high.

Further, the wires on both sides of the substrate 5 can selectively add wires A3 and B4, effectively improving the selectivity of preparing the gradient material 9, making it applicable to a wide range, and no additional heat source heating is required during the preparation process , only by setting the driving device to drive the stirring needle 1 to rotate and rub, which simplifies the additive manufacturing process, and the stirring needle 1 can be used repeatedly, saving the use cost.

In one embodiment of the present invention, since the device of this patent does not limit the difference in the melting points of the two constituent wires, it can increase the types of materials that can be processed in gradients. Therefore, the wire material is preferably but not limited to magnesium alloy, aluminum alloy, and copper alloy. , steel, non-metal, etc., while improving the strength of the gradient material 9, the scope of application of the device is enhanced.

In one embodiment of the present invention, a common driving motor (not shown in the figure) is affixed to the top of the stirring needle 1 , and the rotation of the stirring needle 1 driven by the driving motor is a prior art without further description.

To further optimize the scheme, the wire feeding mechanism includes two wire feeding wheels 8 arranged on one side of the base plate 5, and the adjacent sides of the two wire feeding wheels 8 rotate in the same direction. The two wire feeding channels on both sides are arranged on the same axis, and the two wire materials move towards each other through the two wire feeding channels respectively, and the feeding port is set correspondingly to the discharge end of the wire feeding channel.

To further optimize the scheme, the guide wire mechanism is the static shoulder 2 arranged above the base plate 5, the two feed ports are oppositely opened on the side wall of the static shoulder 2, the stirring needle 1 is arranged in the static shoulder 2, and the feeding trough is connected to the stationary shoulder 2. The feed inlet is set correspondingly, one end of the wire passes through the feed inlet and extends into the feeding trough, and the stirring needle 1 is connected with the stationary shoulder 2 in rotation.

In a further optimization scheme, the feeding trough is a threaded groove opened from top to bottom in a counterclockwise or clockwise direction, the bottom of the feeding trough communicates with the outside of the stirring needle 1, and the stirring needle 1 rotates in the opposite direction of the feeding trough.

When the stirring pin 1 rotates at a high degree, it will generate heat by friction with the stationary shoulder 2, so that the wire A3 and the wire B4 reach a thermoplastic state, and flow to the top of the substrate 5 through the threaded feed chute opened in a counterclockwise or clockwise direction.

Further, feed feed chute A101 and feed feed trough B102 are correspondingly set up corresponding to wire material A3 and wire material B4, and extend into the feed feed chute through feed inlet A201 and feed inlet B202 provided on the stationary shoulder 2 respectively, reducing When the stirring needle 1 rotates, the wires are mixed with each other in the static shoulder 2, which improves the effect of reducing interface defects when preparing the surface layer of the gradient material 9, and the manufacturing direction of the adjacent two wires is opposite to better achieve the gradient preparation. Anisotropy of material 9.

In a further optimized solution, the stationary shoulder 2 slides relative to the base plate 5 , the bottom end of the stirring pin 1 protrudes from the stationary shoulder 2 , and the bottom end of the stirring pin 1 slides in contact with the base plate 5 through the stationary shoulder 2 .

Welding tools (not shown) are used to move the stationary shoulder 2, and the stirring needle 1 is used to rotate, so that the wire material moves to the top surface of the substrate 5 along the spirally descending feeding chute, and the wire material and the material are fully mixed with the stirring needle 103 at the bottom. The surface layer of the substrate 5 increases the preparation area of the first layer material 6 , the second layer material 7 and the gradient material 9 .

And the stirring needle 1 rotates opposite to the opening direction of the feeding chute to ensure the smooth downward movement of the thermoplastic wire, and the diameter of the wire should be controlled to be smaller than the inner wall size of the feeding chute.

In describing the present invention, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", The orientations or positional relationships indicated by "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or It should not be construed as limiting the invention by implying that a referenced device or element must have a particular orientation, be constructed, and operate in a particular orientation.

The above-mentioned embodiments are only to describe the preferred mode of the present invention, and are not intended to limit the scope of the present invention. Variations and improvements should fall within the scope of protection defined by the claims of the present invention.

Claims (10)

1. A method for multi-filament circulation gradient stir friction additive manufacturing, characterized in that: comprising the following steps, S1. Determining the ratio of wire materials: calculate the required proportion of each layer of the gradient material (9) to be prepared, and determine the use of wire A (3) and wire B (4) of different materials on both sides of the substrate (5) Proportion; S2. Setting the wire feeding rate: adjust the wire feeding speed on both sides of the substrate (5), pass the wire material A (3) and the wire material B (4) into both sides of the stirring needle (1) respectively ; S3. Friction additive: Stir and rub the surface of the filament A (3), the filament B (4) and the substrate (5), so that the thermoplastic state of the filament A (3) and the filament Material B (4) is combined with the surface of the substrate (5) to form a first layer of material (6); S4. Gradient material (9) preparation: S3 is repeated until the deposition of the gradient material (9) is completed. 2. The method for multi-filament cyclic gradient stir friction additive manufacturing according to claim 1, characterized in that: in step S3, the stirring needle (1) is rotated at high speed, and the wire A (3) and the The wire material B (4) is transported to the surface of the substrate (5) through the stirring needle (1). 3. The method for multi-filament cyclic gradient stir friction additive manufacturing according to claim 2, characterized in that: in step S3, the stirring needle (1) extends into the thermoplastic filament A (3) and the In the wire material B (4), the substrate (5), the wire material A (3) and the wire material B (4) are rotated by the stirring pin (1) to form the first layer of material ( 6). 4. The method for multi-filament circulating gradient stir friction additive manufacturing according to claim 3, characterized in that: in step S4, the bottom stirring needle (103) fixed to the bottom of the stirring needle (1) extends into the second The length of the layer material (7) or multilayer material is greater than the thickness of the single layer material layer. 5. The method for multi-wire circulation gradient friction stir additive manufacturing according to claim 1, characterized in that: in step S1, the wire materials of different materials are determined according to the required composition ratio of each layer of the gradient material (9) , combined with the rotation speed of the stirring pin (1) to determine the wire feeding rate of the wire. 6. The method for multi-wire circulation gradient stir friction additive manufacturing according to claim 1, characterized in that: in step S2, the wire feeding rate of the conveying wire is adjusted to be consistent with the wire feeding rate calculated in step S1, and The wire material A (3) and the wire material B (4) are respectively passed into the stirring needle (1) through both sides of the stirring needle (1). 7. A device for multi-filament cyclic gradient stir friction additive manufacturing, according to a method for multi-filament cyclic gradient stir friction additive manufacturing according to any one of claims 1-6, characterized in that it includes a substrate (5 ), Two wire feeding mechanisms are arranged on both sides of the base plate (5). The wire feeding mechanism has a discharge end and a feed end. Move towards each other; The wire guide mechanism is arranged above the base plate (5). The wire guide mechanism is provided with two feeding ports corresponding to the discharge ends of the two wire feeding mechanisms, and the wire material extends into the Inside the guide wire mechanism; A stirring needle (1) is arranged in the guide wire mechanism, and a feeding trough is arranged on the side wall of the stirring needle (1), and the feeding trough is used to derive the gradient material (9) for additive manufacturing; The bottom end of the stirring needle (1) protrudes from the wire guide mechanism and is in sliding contact with the top end of the base plate (5), and the stirring needle (1) is rotatably connected with the wire guide mechanism. 8. The device for multi-wire circulation gradient stir friction additive manufacturing according to claim 7, characterized in that: the wire feeding mechanism includes two wire feeding wheels (8) arranged on one side of the substrate (5), The adjacent sides of the two wire feed wheels (8) rotate in the same direction, and the two wire feed wheels (8) cooperate to form a wire feed channel, and the two wire feed channels located on both sides of the base plate (5) They are arranged on the same axis, and the two wire materials respectively move towards each other through the two wire feeding channels, and the feeding port is set correspondingly to the discharge end of the wire feeding channels. 9. The device for multi-filament cyclic gradient stir friction additive manufacturing according to claim 7, characterized in that: the wire guiding mechanism is a stationary shoulder (2) arranged above the substrate (5), and two The feed inlet is relatively opened on the side wall of the stationary shoulder (2), the stirring needle (1) is arranged in the stationary shoulder (2), and the feeding trough and the feed inlet Correspondingly, one end of the wire passes through the feeding port and extends into the feeding trough, and the stirring needle (1) is rotatably connected with the stationary shoulder (2). 10. The device for multi-filament cyclic gradient stir friction additive manufacturing according to claim 7, characterized in that: the feeding trough is a threaded groove opened counterclockwise or clockwise from top to bottom, and the feeding chute is The bottom end of the material trough communicates with the outside of the stirring needle (1), and the stirring needle (1) rotates along the opposite direction of the material delivery trough.

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