Device and method for inhibiting abnormal growth of crystal grains in solid-phase additive manufacturing

Abstract

The invention relates to a device and a method for inhibiting abnormal growth of crystal grains in solid-phase additive manufacturing, in particular to a device and a method for inhibiting abnormal growth of crystal grains in solid-phase additive manufacturing. The invention aims to solve the problems that the existing reinforced phase particle introduction process is complicated and low in efficiency. The device comprises a wire feeding machine, a material adding tool is arranged on the right side of the wire feeding machine, a mounting disc is arranged on the material adding tool, and a drying machine, a coating mechanism and a wire cleaning mechanism are sequentially arranged on the left side of the wire feeding machine. According to the method, introduction of the reinforced phase particles is synchronously completed in the material adding process, the problems that the introduction process of the particle reinforced phase is complex, the efficiency is low and the like are solved, and a new technical scheme is provided for inhibiting abnormal grain growth occurring in the heat treatment process of a solid-phase material adding manufacturing component. The invention belongs to the technical field of solid phase additive manufacturing.

Description

Technical Field

[0001] This invention relates to an apparatus and method for suppressing abnormal grain growth, belonging to the field of solid-state additive manufacturing technology. Background Technology

[0002] Solid-state additive manufacturing is an additive manufacturing method that utilizes frictional heat and heat of large plastic deformation as heat sources. During the additive manufacturing process, the material does not undergo melting and solidification. In the additive manufacturing of lightweight alloys such as aluminum, magnesium, and zinc alloys, it can effectively avoid defects such as porosity, cracks, and thermal stress. The microstructure after additive manufacturing exhibits fine equiaxed grains due to the significant recovery-recrystallization process. Solid-state additive products are now widely used in aerospace, rail transportation, and other fields.

[0003] Because a large amount of deformation is introduced into the matrix during solid-state additive manufacturing, it cannot be completely released after additive manufacturing. Although some deformation energy is consumed through the recovery-recrystallization process, a considerable portion of the deformation energy remains in the microstructure. For heat-treatable aluminum alloys such as 2-series, 6-series, and 7-series aluminum alloys, during solution treatment, when the strengthening phase melts back into the aluminum matrix, the pinning effect of grain boundaries is greatly weakened. The deformation energy stored in the matrix drives grain boundary migration, resulting in abnormal grain growth, with some grains growing to the millimeter level. The coarsened microstructure leads to a significant decrease in the mechanical properties of the component, making its performance unable to meet practical requirements.

[0004] Introducing reinforcing phase particles into the matrix to pin grain boundaries is a common method to suppress abnormal grain growth during heat treatment. Currently, commonly used methods include powder metallurgy, semi-solid direct extrusion casting, and stirred casting. However, powder metallurgy, when preparing large-sized components, struggles to ensure uniform powder stress, easily leading to insufficient density and high porosity, and is unsuitable for large-scale manufacturing of components with complex paths. In semi-solid direct extrusion casting, when preparing aluminum-based composite components, the reinforcing phase particles often differ from the aluminum matrix in density and flowability, leading to particle agglomeration and reduced reinforcing effect. When using stirred casting to prepare large-sized structural parts, the large cavity volume and long flow path, coupled with the increased viscosity of the molten aluminum due to the addition of reinforcing phase particles, further reduce flowability, making it prone to premature solidification of the molten aluminum at the front end during filling, resulting in insufficient filling at the far end or in complex areas and causing macroscopic defects.

[0005] In summary, introducing reinforcing phase particles to suppress abnormal grain growth during heat treatment faces the following challenges: 1. The reinforcing phase is prone to agglomeration, which can lead to a decrease in the reinforcing effect or damage to the performance of the component; 2. The process is complex and cumbersome, resulting in low production efficiency and low product qualification rate; 3. Technical limitations exist when manufacturing complex paths or large-sized components, making it impossible to quickly manufacture parts on demand.

[0006] Therefore, there is an urgent need to propose a device and method for suppressing abnormal grain growth in solid-phase additive manufacturing. Summary of the Invention

[0007] To address the problems of complex and inefficient existing processes for introducing reinforcing phase particles, this invention proposes a device and method for suppressing abnormal grain growth in solid-phase additive manufacturing.

[0008] The technical solution adopted by the present invention to solve the above problems is as follows: The device for suppressing abnormal grain growth in solid-phase additive manufacturing includes a wire feeder, an additive tool is provided on the right side of the wire feeder, an installation plate is provided on the additive tool, and a dryer, a coating mechanism and a wire cleaning mechanism are arranged sequentially on the left side of the wire feeder.

[0009] Furthermore, the wire cleaning mechanism includes a base plate on which two brushless motors are arranged side by side. The motor shaft of each brushless motor is connected to a planetary drive assembly, which is connected to a sun gear. A rotating wire brush cleaner is installed inside the sun gear.

[0010] Furthermore, the planetary drive assembly includes a bracket fixed to the upper surface of the base plate. The bracket has two drive shafts, each with a planetary gear that meshes with the sun gear. The drive shafts also have pulleys that are connected to the motor shaft of the brushless motor via a belt.

[0011] Furthermore, the coating mechanism includes a storage tank with two through holes symmetrically arranged at both ends. Each through hole contains a rubber ring. The storage tank contains a stirrer, and the bottom of the storage tank contains an ultrasonic vibration device.

[0012] Furthermore, a liquid level sensor is installed on the side wall inside the storage tank.

[0013] Furthermore, the additive tool includes a screw, the lower part of which is fitted with an additive sleeve.

[0014] Furthermore, the lower end of the additive sleeve is provided with a forging plane, and the side wall of the additive sleeve is provided with a lateral feed hole.

[0015] Furthermore, the upper part of the screw is provided with a clamping part, the lower part of the screw is provided with a transmission part, and the lower end of the screw is provided with a bottom stirring part.

[0016] The method for suppressing abnormal grain growth in solid-state additive manufacturing according to the present invention includes the following steps: Step 1: Adjust the filament feeder, filament cleaning mechanism, and coating mechanism through the support mechanism to match the height of the feed hole in the additive manufacturing tool, ensuring continuous feeding. Step 2: Clean and roughen the surface of the wire material; Step 3: After roughening treatment, the surface of the filament material is coated with a uniform reinforcing phase particle gel. Step 4: The filament with reinforcing phase particle gel is passed through the dryer at a uniform speed to complete the introduction of the reinforcing phase particle gel; Step 5: The additive manufacturing tool is started. The screw rotates at a speed of 250~1000 rpm and moves along a preset path at a speed of 100~1000 rpm. The additive sleeve and the mounting plate remain relatively stationary and do not rotate. The filament passes through the feed hole at a speed of 1~10 m / min. When it reaches the threaded section, the filament is sheared and moves to the bottom stirring section under the action of the threaded transmission section. Under the action of the bottom stirring section, the deposition process is completed through friction between the filament and the additive sleeve and the substrate.

[0017] The beneficial effects of this invention are: 1. This invention solves the problem of abnormal grain growth during component heat treatment by designing a device and method to suppress abnormal grain growth in solid-phase additive manufacturing, which simultaneously introduces reinforcing phase particles into the matrix during the additive manufacturing process. 2. The coating device designed in this invention is equipped with a paddle and an ultrasonic device, which achieves the effect of uniform texture and particle dispersion of the reinforcing phase particles gel; 3. This invention achieves an integrated coating-drying design, avoiding secondary transfer after coating the reinforcing phase particle gel, optimizing production steps, and reducing production costs; 4. Based on this invention, existing lightweight alloy wires such as aluminum alloys and magnesium alloys can be customized with reinforcing phase particle gels of different compositions on their surfaces, enabling rapid customized coating of the wire surface composition and simultaneous additive manufacturing, which greatly expands the range of raw materials for solid phase additive manufacturing. 5. Based on the present invention, the reinforcing phase particles are introduced simultaneously during the solid-phase additive manufacturing process. The reinforcing phase is evenly dispersed in the microstructure of the prepared component, and the grain size is small and uniform after heat treatment, resulting in high mechanical properties. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the working principle of the present invention; Figure 2 This is a schematic diagram of the wire cleaning mechanism; Figure 3 This is a schematic diagram of the coating mechanism; Figure 4 This is a structural schematic diagram of an additive manufacturing tool; Figure 5 This is a schematic diagram illustrating the principle of suppressing abnormal grain growth. Figures 1 to 4In the middle section, 1-Wire cleaning mechanism, 101-Brushless motor, 102-Pulley, 103-Belt, 104-Planetary gear, 105-Sun gear, 106-Rotary wire brush cleaner, 107-Drive shaft, 108-Bracket, 2-Coating mechanism, 201-Rubber ring, 202-Storage hopper, 203-Agitator, 204-Level sensor, 205-Ultrasonic vibration device, 3-Dryer, 4-Wire feeder, 5-Additive tool, 501-Additive sleeve, 50101-Side feed hole, 50102-Forging plane, 502-Screw, 50201-Clamping part, 50202-Transmission part, 50203-Bottom stirring part, 6-Protective cover, 7-Mounting plate. Detailed Implementation

[0019] Specific implementation method one: as follows Figure 1 As shown, an apparatus for suppressing abnormal grain growth in solid-state additive manufacturing includes a wire feeder 4. A dryer 3, a coating mechanism 2, and a wire cleaning mechanism 1 are arranged sequentially on the left side of the wire feeder 4. An additive manufacturing tool 5 is arranged on the right side of the wire feeder 4, and an installation plate 7 is provided on the additive manufacturing tool 5. The wire passes through the wire cleaning mechanism 1 and the coating mechanism 2 in sequence and then enters the wire feeder 4. The wire feeder 4 transports the wire to the additive manufacturing tool 5.

[0020] In some embodiments, a protective cover 6 is also included, and the filament cleaning mechanism 1, the coating mechanism 2 and the dryer 3 are all located inside the protective cover 6.

[0021] During equipment operation, the filament sequentially passes through the annular rotating steel wire brush cleaner 106 in the filament cleaning mechanism to remove surface impurities such as oxide film and oil, while simultaneously roughening the filament surface to facilitate subsequent coating of reinforcing phase particle gel. It then continues through the coating mechanism 2, which has a built-in liquid level sensor 204 to monitor the liquid level and a lower ultrasonic device 205 to prevent metal particle agglomeration. The coated filament then passes through the dryer 3, which incorporates a large-area resistance wire for rapid drying. The dried aluminum-based composite filament passes through the feed hole 50102 in the additive sleeve 501. The filament cleaning mechanism 1 is fixed to the bottom worktable via a bracket 108, and the coating mechanism 2 is fixedly connected to the protective cover 6 via a restraining steel band. The dryer 3 is fixedly connected to the upper protective cover 6 via bolts. Specific implementation method two: such as Figure 2 As shown, the wire cleaning mechanism 1 includes a base plate, on which two supports 108 are arranged side by side. Each support 108 has two drive shafts 107 arranged from top to bottom. Planetary gears 104 are mounted on the drive shafts 107. A sun gear 105 is provided between the two drive shafts 107. A through hole is provided in the sun gear 105. A rotary wire brush cleaner 106 is provided in the through hole. The wire passes through the through hole on the left end face of the protective cover 6 and then passes through the rotary wire brush cleaner 106. Two brushless motors 101 are arranged side by side on the base plate. Each drive shaft 107 is fitted with a pulley 102. The pulley on the motor shaft of the brushless motor 101 is connected to the pulley 102 on the drive shaft 107 via a belt 13.

[0022] The drive shaft 107 is connected to the planetary gear 104 by a flat key, and the rotary wire brush cleaner 106 is connected to the sun gear 105 by an interference fit.

[0023] Specific implementation method three: such as Figure 3 As shown, the coating mechanism 2 includes a storage tank 202. The storage tank 202 has a through hole in the middle of both end faces. A rubber ring 201 is provided in the through hole. After the filament is cleaned by the filament cleaning mechanism 1, it passes through the two rubber rings 201 in sequence. A stirrer 203 is provided in the storage tank 202. An ultrasonic vibration device 205 is provided at the bottom of the storage tank 202. In order to monitor the liquid level in the storage tank 202 at any time, a liquid level sensor 204 is installed on the side wall inside the storage tank 202.

[0024] The agitator 203 is connected to the upper protective cover 6 by fastening screws and is driven by an external motor. Openings are made on both sides of the storage tank, and rubber pads 201 are placed there. The inner diameter 201 of the rubber pads matches the diameter of the wire. A liquid level sensor 204 mounted on the storage tank forms a capacitor with the storage tank 202. When the liquid level drops, the area of ​​the liquid covering the electrode decreases, and the capacitance value decreases. The sensor detects the change in capacitance value to measure the change in liquid level height and synchronizes the information to the terminal via a signal transmitting device.

[0025] Specific implementation method four: such as Figure 4 As shown, the additive tool 5 includes a screw 502, and an additive sleeve 501 is fitted onto the lower part of the screw 502; The lower end of the additive sleeve 501 is provided with a forging plane 50102, and the side wall of the additive sleeve 501 is provided with a lateral feed hole 50101. The upper part of the screw 502 is provided with a clamping part 50201, the lower part of the screw 50201 is provided with a transmission part 50202, and the lower end of the screw 50201 is provided with a bottom stirring part 50203.

[0026] The screw 502 has a pitch of 10~40mm, including but not limited to single thread, double thread, triple thread and other designs. The inner wall of the additive sleeve 501 is 0.1~1mm larger than the major diameter of the threaded part. The additive sleeve 501 and the mounting plate 7 are fastened together by screws. When the wire is fed into the sleeve, the screw shears the wire into particles during high-speed rotation and transmits them downward through the conveying section. When plasticization occurs under the action of the bottom stirring section 50203, the additive manufacturing process begins. The plasticized material is subjected to the forging action of the forging plane 50102 at the bottom of the additive sleeve 501 during the movement of the spindle, thereby obtaining a dense and defect-free aluminum alloy structure.

[0027] like Figure 5 The diagram shows the mechanism of the present invention for suppressing abnormal grain growth during heat treatment. The microstructure without reinforcing phase particles exhibits abnormal grain growth after solution treatment, while the solid additive microstructure with reinforcing phase particles retains a fine equiaxed grain structure during solution treatment because the grain boundaries are pinned by fine and dispersed reinforcing phase particles.

[0028] Specific implementation method five: such as Figures 1 to 4 As shown, a method for suppressing abnormal grain growth in solid-state additive manufacturing includes the following steps: Step 1: Adjust the wire feeder 4, wire cleaning mechanism 1, and coating mechanism 2 through the support mechanism to match the height of the above devices with the feed hole 50101 in the additive tool to ensure continuous feeding. Step 2: Clean and roughen the surface of the wire material; Step 3: After roughening treatment, the surface of the filament material is coated with uniform reinforcing phase particle gel under the action of coating mechanism 2; Step 4: The filament with reinforcing phase particle gel passes through the dryer 3 at a uniform speed to complete the introduction of the reinforcing phase particle gel; Step 5: The additive manufacturing tool is started. The screw 502 rotates at a speed of 250~1000 rpm and moves along a preset path at a speed of 100~1000 rpm. The additive sleeve 501 remains relatively stationary with respect to the mounting plate 7 and does not rotate. The filament passes through the feed hole at a speed of 1~10 m / min. When it reaches the threaded section, the filament is sheared and moves to the bottom stirring section 50203 under the action of the threaded transmission section. Under the action of the bottom stirring section 50203, the deposition process is completed through friction between the filament and the additive sleeve and the substrate.

[0029] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A device for suppressing abnormal grain growth in solid-state additive manufacturing, characterized in that, The device includes a wire feeder (4), an additive manufacturing tool (5) on the right side of the wire feeder (4), an installation plate (7) on the additive manufacturing tool (5), and a dryer (3), a coating mechanism (2) and a wire cleaning mechanism (1) on the left side of the wire feeder (4).

2. The apparatus for suppressing abnormal grain growth in solid-state additive manufacturing according to claim 1, characterized in that, The wire cleaning mechanism (1) includes a base plate on which two brushless motors (101) are arranged side by side. Each brushless motor (101) has a planetary drive assembly connected to its motor shaft. The planetary drive assembly is connected to a sun gear (105). A rotary wire brush cleaner (106) is installed inside the sun gear (105).

3. The apparatus for suppressing abnormal grain growth in solid-state additive manufacturing according to claim 2, characterized in that, The planetary drive assembly includes a bracket (108) fixed to the upper surface of the base plate. The bracket (108) is provided with two drive shafts (107), each drive shaft (107) is provided with a planetary gear (104), the planetary gear (104) meshes with the sun gear (105), and the drive shaft (107) is also provided with a pulley (102), the pulley (102) is connected to the motor shaft of the brushless motor (101) through a belt (103).

4. The apparatus for suppressing abnormal grain growth in solid-state additive manufacturing according to claim 1, characterized in that, The coating mechanism (2) includes a storage tank (202), with two through holes symmetrically provided at both ends of the storage tank (202), a rubber ring (201) provided in each through hole, a stirrer (203) provided in the storage tank (202), and an ultrasonic vibration device (205) provided at the bottom of the storage tank (202).

5. The apparatus for suppressing abnormal grain growth in solid-state additive manufacturing according to claim 4, characterized in that, A liquid level sensor (204) is installed on the side wall inside the storage tank (202).

6. The apparatus for suppressing abnormal grain growth in solid-state additive manufacturing according to claim 1, characterized in that, The additive tool (5) includes a screw (502) with an additive sleeve (501) fitted on the lower part of the screw (502).

7. The apparatus for suppressing abnormal grain growth in solid-state additive manufacturing according to claim 6, characterized in that, The lower end of the additive sleeve (501) is provided with a forging plane (50102), and the side wall of the additive sleeve (501) is provided with a lateral feed hole (50101).

8. The apparatus for suppressing abnormal grain growth in solid-state additive manufacturing according to claim 6, characterized in that, The upper part of the screw (502) is provided with a clamping part (50201), the lower part of the screw (50201) is provided with a transmission part (50202), and the lower end of the screw (50201) is provided with a bottom stirring part (50203).

9. A method for suppressing abnormal grain growth in solid-state additive manufacturing, characterized in that, The specific steps include: Step 1: Adjust the wire feeder (4), wire cleaning mechanism (1), and coating mechanism (2) through the support mechanism to match the height of the above devices with the feed hole (50101) in the additive tool to ensure continuous feeding; Step 2: Clean and roughen the surface of the wire material; Step 3: After roughening treatment, the surface of the filament material is coated with uniform reinforcing phase particle gel under the action of the coating mechanism (2); Step 4: The filament with reinforcing phase particle gel passes through the dryer (3) at a uniform speed to complete the introduction of the reinforcing phase particle gel; Step 5: The additive manufacturing tool is started. The screw (502) rotates at a speed of 250~1000 rpm and moves along a preset path at a speed of 100~1000 rpm. The additive sleeve (501) and the mounting plate (7) remain relatively stationary and do not rotate. The filament passes through the feed hole at a speed of 1~10 m / min. When it is fed to the threaded part, the filament is sheared and moves to the bottom stirring part (50203) under the action of the threaded transmission part. Under the action of the bottom stirring part (50203) and the friction between the additive sleeve and the substrate, the deposition process is completed.

Images