Particle-reinforced aluminum-based composite material based on foil stirring friction processing and preparation method of particle-reinforced aluminum-based composite material

Abstract

The invention discloses a particle reinforced aluminum-based composite material based on foil stirring friction processing and a preparation method thereof. The preparation method comprises the following steps that an aluminum cover plate, an aluminum foil, an aluminum substrate and an M metal foil are pretreated; the pretreated materials are stacked into a machining unit, the surface layer of the machining unit is an aluminum cover plate, the bottom layer of the machining unit is an aluminum substrate, the middle layer of the machining unit is a single-layer or multi-layer M metal foil, and when the number of the M metal foils is multiple, aluminum foil is arranged between every two layers of M metal foils; the machining unit is fixed to a workbench of a friction stir welding machine tool, a stirring head is controlled to rotate and press downwards, a stirring needle of the stirring head is inserted into the machining unit and enters the aluminum substrate, meanwhile, a shaft shoulder of the stirring head makes full contact with the aluminum cover plate, the pressing amount is well controlled, and then friction stir machining is conducted on different positions of the machining unit. And the particle-reinforced aluminum-based composite material plate is prepared. Solid-phase forming can be achieved at the room temperature, the process is simple, energy is saved, environment friendliness is achieved, metallurgical defects such as pores and microcracks do not exist, and the yield is high.

Description

Technical Field

[0001] The invention belongs to the field of metal-based composite materials and relates to a particle-reinforced aluminum-based composite material based on foil friction stir processing and a preparation method thereof. Background Art

[0002] Aluminum-based composite materials have excellent properties such as low density, high strength, easy processing, and corrosion resistance. They are important materials for manufacturing aerospace and rail transportation structural parts. Their application helps to achieve lightweight equipment, increase operating speed, and reduce energy consumption. At present, common particle-reinforced aluminum-based composite material preparation technologies mainly include powder metallurgy, stirring casting, in-situ reaction synthesis and other methods. When using these methods to prepare particle-reinforced aluminum-based composite materials, it is often necessary to mix the reinforcement powder or reactant powder and add it to the raw material aluminum powder or molten aluminum liquid, and then prepare and form it under high temperature and high pressure conditions. The process is complex and the energy consumption is high. In addition, the preparation cost of powder raw materials is high, and aluminum powder is prone to explosion hazards, has high requirements for the transportation process and storage environment, and has poor safety.

[0003] In recent years, the low-energy, pollution-free friction stir processing (FSP) technique has been increasingly used to prepare and form particle-reinforced aluminum-based composites. However, current methods require prefabricating holes and grooves in aluminum plates, which wastes material, increases processing costs, and reduces production efficiency. Furthermore, these methods still fail to address the high production costs and poor storage safety of powdered raw materials. Therefore, there is an urgent need to develop an efficient, energy-saving, safe, and environmentally friendly method for preparing particle-reinforced aluminum-based composites. Summary of the Invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a particle-reinforced aluminum-based composite material based on foil stir friction processing and a preparation method thereof, so as to solve the problems that most of the existing particle-reinforced aluminum-based composite material preparation methods use powder as the reinforcement raw material, which have high raw material processing costs, insufficient material utilization, storage difficulties, low production efficiency, and high energy consumption.

[0005] Technical solution: A method for preparing a particle-reinforced aluminum-based composite material based on foil friction stir processing of the present invention comprises the following steps:

[0006] S1. Pretreatment: The aluminum cover plate, aluminum foil, aluminum substrate and M metal foil as the raw material of the reinforcement are used as processing substrates and cleaned;

[0007] S2. Stacking the pretreated aluminum cover plate, aluminum foil, M metal foil, and aluminum substrate into a processing unit, wherein the surface layer of the processing unit is the aluminum cover plate, the bottom layer is the aluminum substrate, and the middle layer is a single layer or multiple layers of M metal foil. When the M metal foil is multiple layers, aluminum foil is provided between each layer of M metal foil;

[0008] S3, fixing the processing unit in step S2 to the workbench of the friction stir welding machine, controlling the stirring head to rotate and press downward, so that the stirring needle is inserted into the processing unit and enters the aluminum substrate, while the shaft shoulder of the stirring head is in full contact with the aluminum cover plate and the downward pressure is controlled, and starting the stirring head to move straight from one end of the processing unit to the other end to complete a single-pass single-layer friction stir processing;

[0009] S4. Repeat the single-pass single-layer friction stir processing process in step S3 at different positions of the processing unit until the friction stir processing of the entire processing unit is completed to obtain a particle-reinforced aluminum-based composite material plate.

[0010] Furthermore, the M metal foil is selected from one or a combination of pure metal foil, alloy foil, or aluminum foil coated with a reinforcement phase. The coating material of the aluminum foil coated with a reinforcement phase includes but is not limited to ceramic particles and carbon nanotubes.

[0011] Furthermore, the aluminum cover plate, aluminum foil and aluminum substrate are made of aluminum alloy or pure aluminum.

[0012] Furthermore, the specific method of step S1 is as follows: remove the oil stains on the surfaces of the aluminum cover plate, aluminum foil, aluminum substrate and M metal foil with acetone, wipe them clean with anhydrous ethanol, and dry them in air for later use.

[0013] Furthermore, in the stir friction processing of steps S3 and S4, the shoulder diameter of the stirring head is 15 to 22 mm, the stirring needle is conical, the root diameter of the stirring needle is 6 to 8 mm, the top diameter is 5 to 6 mm, the needle length is 1.8 to 5.5 mm, and the material of the stirring head is H13 tool steel or tungsten-rhenium alloy; the rotation speed of the stirring head during processing is 500 to 1400 r / min, the processing speed is 10 to 150 mm / min, the downward pressure is 0.02 to 0.2 mm, and the stirring head has no tilt angle.

[0014] Furthermore, during the friction stir processing in steps S3 and S4, argon gas is used as the protective atmosphere.

[0015] Furthermore, in step S3, a copper alloy or stainless steel pad with a thickness of 3 to 12 mm is placed between the processing unit and the workbench.

[0016] Furthermore, the method further includes repeating steps S3 and S4 to perform multiple friction stir processing processes to improve the uniformity of the particle reinforcement and reduce the size of the particles.

[0017] Furthermore, the method further includes step S5 of heat treating the prepared particle reinforced aluminum-based composite material plate.

[0018] The present invention provides a particle reinforced aluminum-based composite material based on foil friction stir processing, which is prepared by adopting the preparation method of the particle reinforced aluminum-based composite material based on foil friction stir processing.

[0019] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0020] (1) The present invention proposes to use pure metal or alloy foil as the raw material of the reinforcement, and utilize friction heat plasticization and stirring to break the foil into particles and disperse them along the plastic flow of the three-dimensional metal near the stirring needle, thereby obtaining a particle-reinforced aluminum-based composite material. This method can realize solid-phase forming at room temperature, has a simple process, is energy-saving and environmentally friendly, does not have metallurgical defects such as pores and microcracks, and has a high yield rate, thus overcoming the shortcomings of traditional methods such as high process difficulty, high energy consumption, and high cost caused by the high temperature and high pressure effects.

[0021] (2) The present invention uses metal foil as the raw material or carrier of the reinforcement. The raw material is widely available, which solves the problems faced by the traditional method of using powder as the raw material for forming, such as high raw material processing cost, flammability, explosion and difficulty in storage of metal powder.

[0022] (3) The present invention can arbitrarily select the composition of the aluminum plate, aluminum foil and reinforcement foil, the thickness of the single-layer foil, the thickness of the plate, the number of foil stacking layers and the stacking order according to the design requirements, and can easily realize the controllable preparation of aluminum-based composite materials with different specifications, different compositions, different particle types and contents.

[0023] (4) The present invention can change the size and distribution state of the reinforcement particles by adjusting the number of stir friction processing passes; it can also obtain aluminum-based composite materials with different reinforcement particle compositions and precipitation-equivalent microstructural characteristics by combining different process conditions and their combined forms of heat treatment, thereby obtaining different performance matching and excellent comprehensive mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a processing diagram of the present invention.

[0025] Figure 2 This is the organizational structure of the titanium particle reinforced aluminum-based composite material prepared in Example 1, where (a) is the macroscopic morphology of the processing area, (b) is a local magnified view, (c) is the aluminum element distribution map, and (d) is the titanium element distribution map.

[0026] Figure 3 This is the organizational structure of the 304 stainless steel particle reinforced aluminum-based composite material prepared in Example 2.

[0027] Figure 4These are metallographic photographs of the 304 stainless steel particle-reinforced aluminum-based composite material subjected to reaction annealing treatment in Example 3, wherein (a) shows that the 304 stainless steel and aluminum completely reacted to form intermetallic compound particles, and (b) shows that the 304 stainless steel and aluminum partially reacted to form particles with a core-shell structure. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] like Figure 1 As shown, a method for preparing a particle reinforced aluminum-based composite material based on foil friction stir processing includes the following steps:

[0030] S1. Pretreatment: The aluminum cover plate 31, the aluminum foil 34, the aluminum substrate 32 and the M metal foil 33 as the raw material of the reinforcement are used as processing substrates and cleaned;

[0031] S2. Stacking the pretreated aluminum cover plate 31, aluminum foil 34, M metal foil 33, and aluminum substrate 32 into a processing unit 3, wherein the surface layer of the processing unit 3 is the aluminum cover plate 31, the bottom layer is the aluminum substrate 32, and the middle layer is a single layer or multiple layers of M metal foil 33. When the M metal foil 33 is multiple layers, aluminum foil 34 is provided between each layer of M metal foil 33. That is, from top to bottom, the processing unit is stacked in the order of "aluminum cover plate - M metal foil - aluminum foil - M metal foil - aluminum foil - ... - M metal foil - aluminum substrate";

[0032] S3, fixing the processing unit 3 in step S2 to the workbench of the friction stir welding machine, controlling the stirring head 1 to rotate and press downward, so that the stirring needle 2 is inserted into the processing unit 3 and enters the aluminum substrate 32 to a certain depth, while the shaft shoulder of the stirring head 1 is in full contact with the aluminum cover plate 31 and the downward pressure is controlled, and starting the stirring head 1 to move straightly from one end of the processing unit to the other end to complete a single-pass single-layer friction stir processing;

[0033] S4. Repeat the single-pass single-layer friction stir processing process in step S3 at different positions of the processing unit 3 until the friction stir processing of the entire processing unit 3 is completed to obtain a particle-reinforced aluminum-based composite material plate.

[0034] Example 1

[0035] (1) Processing and cutting a rolled AA1100 pure aluminum plate with a length × width × thickness = 100 mm × 100 mm × 6 mm as an aluminum substrate, processing and cutting a rolled AA1100 pure aluminum plate with a length × width × thickness = 100 mm × 100 mm × 2 mm as an aluminum cover plate, processing and cutting a AA1100 pure aluminum foil with a length × width × thickness = 100 mm × 100 mm × 0.2 mm, and processing and cutting a TA2 pure titanium foil with a length × width × thickness = 100 mm × 100 mm × 0.2 mm as the M metal foil material of the reinforcement raw material;

[0036] (2) Remove the oil stains on the surface of the aluminum cover plate, aluminum substrate, pure aluminum foil, and pure titanium foil with acetone, wipe them clean with anhydrous ethanol, and dry them in air;

[0037] (3) The cleaned aluminum cover plate, pure aluminum foil, pure titanium foil, and aluminum substrate are stacked into a processing unit in the order of "2mm Al-TA2-0.2mm Al-TA2-6mm Al" from top to bottom, and fixed to the workbench of the stir friction welding machine. A 6mm thick stainless steel pad is placed between the stacking unit and the workbench to prevent the aluminum plate from overheating and connecting to the workbench;

[0038] (4) An H13 steel stirring tool head with a shoulder diameter of 18 mm and a stirring needle length of 1.8 mm was installed on the stir friction welding machine. The process parameters were set as follows: the stirring head rotated clockwise, the speed was 800 r / min, the processing speed was 100 mm / min, the downward pressure was 0.1 mm, and the stirring head had no inclination angle. Subsequently, the stacking unit was processed in multiple passes using the stir friction welding equipment to obtain titanium particle reinforced aluminum-based composite material plates.

[0039] The microstructure and element distribution of the prepared titanium particle reinforced aluminum matrix composite are as follows: Figure 2 As shown, it can be seen that after stirring, crushing and three-dimensional flow of the plastic matrix, the continuous titanium foil in the processing area becomes dispersed multi-scale titanium particles. The element analysis results show that there is no chemical reaction between titanium and aluminum, and the interface bonding is good.

[0040] Example 2

[0041] (1) a rolled AA6061 aluminum alloy plate with a length × width × thickness = 150 mm × 150 mm × 3 mm was processed and cut as an aluminum base plate, a rolled AA6061 aluminum alloy plate with a length × width × thickness = 150 mm × 150 mm × 1 mm was processed and cut as an aluminum cover plate, and a 304 stainless steel foil with a length × width × thickness = 150 mm × 150 mm × 0.1 mm was processed and cut as the M metal foil material of the reinforcement raw material;

[0042] (2) Remove the oil stains on the surface of the aluminum cover plate, aluminum substrate, and 304 stainless steel foil with acetone, wipe them clean with anhydrous ethanol, and dry them in air;

[0043] (3) The cleaned aluminum cover plate, 304 stainless steel foil, and aluminum substrate were stacked into a processing unit in the order of "1 mm Al-304 foil-3 mm Al" from top to bottom, and fixed to the workbench of the friction stir welding machine. A 6 mm thick copper plate was placed between the stacking unit and the workbench to prevent the aluminum plate from overheating and connecting to the workbench.

[0044] (4) An H13 steel stirring tool head with a shoulder diameter of 18 mm and a stirring needle length of 1.8 mm was installed on a friction stir welding machine. The process parameters were set as follows: the stirring head rotated clockwise, the speed was 1000 r / min, the processing speed was 50 mm / min, the downward pressure was 0.15 mm, and the stirring head had no inclination angle. Subsequently, the stacked unit was processed in multiple passes using the friction stir welding equipment to obtain a 304 stainless steel particle reinforced aluminum matrix composite plate.

[0045] The microstructure of the prepared 304 stainless steel particle reinforced aluminum matrix composite material is as follows: Figure 3 As shown in the figure, it can be seen that after friction stir processing, the continuous 304 stainless steel foil becomes dispersed multi-scale 304 stainless steel particles, and the interface between the reinforcement particles and the matrix is well bonded.

[0046] Example 3

[0047] (1) a rolled AA6061 aluminum alloy plate with a length × width × thickness = 150 mm × 150 mm × 3 mm was processed and cut as an aluminum base plate, a rolled AA6061 aluminum alloy plate with a length × width × thickness = 150 mm × 150 mm × 1 mm was processed and cut as an aluminum cover plate, and a 304 stainless steel foil with a length × width × thickness = 150 mm × 150 mm × 0.1 mm was processed and cut as the M metal foil material of the reinforcement raw material;

[0048] (2) Remove the oil stains on the surface of the aluminum cover plate, aluminum substrate, and 304 stainless steel foil with acetone, wipe them clean with anhydrous ethanol, and dry them in air;

[0049] (3) The cleaned aluminum cover plate, 304 stainless steel foil, and aluminum substrate were stacked into a processing unit in the order of "1 mm Al-304 foil-3 mm Al" from top to bottom, and fixed to the workbench of the friction stir welding machine. A 6 mm thick copper plate was placed between the stacking unit and the workbench to prevent the aluminum plate from overheating and connecting to the workbench.

[0050] (4) An H13 steel stirring tool head with a shoulder diameter of 18 mm and a stirring needle length of 1.8 mm was installed on a friction stir welding machine. The process parameters were set as follows: the stirring head rotated clockwise, the speed was 1000 r / min, the processing speed was 50 mm / min, the downward pressure was 0.15 mm, and the stirring head had no inclination angle. Subsequently, the stacked unit was processed in multiple passes using the friction stir welding equipment to obtain a 304 stainless steel particle reinforced aluminum matrix composite plate.

[0051] (5) The prepared 304 stainless steel particle reinforced aluminum matrix composite plate was subjected to reaction annealing treatment, and the process was as follows: heating to 600 °C, keeping warm for 10 min, and then cooling by air cooling + water cooling. The reaction process was carried out in air atmosphere;

[0052] The microstructure of the finally prepared 304 stainless steel particle reinforced aluminum matrix composite material is as follows: Figure 4 As shown, compared to the 304 stainless steel particle-reinforced aluminum-based composite material that has not undergone reaction annealing (i.e., Example 2), after heat treatment at 600°C / 10 min, some fine 304 stainless steel particles completely react with aluminum to transform into intermetallic compound particles, while some coarse stainless steel particles partially react with aluminum to form a core-shell structure, i.e., composite reinforcement particles with the intermetallic compound as the shell and the 304 stainless steel as the core. The interfaces between these reinforcement particles and the matrix are well bonded. This shows that by coordinating the size of the particle reinforcement and the reaction annealing process conditions, particle-reinforced aluminum-based composite materials with different characteristics can be obtained, thereby enhancing their performance matching capabilities and broadening their application prospects.

[0053] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also within the scope of protection of the present invention.

Claims

1. A method for preparing a particle-reinforced aluminum-based composite material based on foil friction stir processing, characterized in that: The following steps are involved: S1. Pretreatment: The aluminum cover plate, aluminum foil, aluminum substrate and M metal foil as the raw material of the reinforcement are used as processing substrates and cleaned; S2. Stacking the pretreated aluminum cover plate, aluminum foil, M metal foil, and aluminum substrate into a processing unit, wherein the surface layer of the processing unit is the aluminum cover plate, the bottom layer is the aluminum substrate, and the middle layer is a single layer or multiple layers of M metal foil. When the M metal foil is multiple layers, aluminum foil is provided between each layer of M metal foil; S3, fixing the processing unit in step S2 to the workbench of the friction stir welding machine, controlling the stirring head to rotate and press downward, so that the stirring needle is inserted into the processing unit and enters the aluminum substrate, while the shaft shoulder of the stirring head is in full contact with the aluminum cover plate and the downward pressure is controlled, and starting the stirring head to move straight from one end of the processing unit to the other end to complete a single-pass single-layer friction stir processing; S4. Repeat the single-pass single-layer friction stir processing process in step S3 at different positions of the processing unit until the friction stir processing of the entire processing unit is completed to obtain a particle-reinforced aluminum-based composite material plate.

2. The method for preparing a particle-reinforced aluminum-based composite material based on foil friction stir processing according to claim 1, characterized in that: The M metal foil is selected from one or a combination of pure metal foil, alloy foil or aluminum foil coated with a reinforcement phase.

3. The method for preparing a particle-reinforced aluminum-based composite material based on foil friction stir processing according to claim 1, characterized in that: The aluminum cover plate, aluminum foil and aluminum base plate are made of aluminum alloy or pure aluminum.

4. The method for preparing a particle-reinforced aluminum-based composite material based on foil friction stir processing according to claim 1, characterized in that: The specific method of step S1 is as follows: remove the oil stains on the surface of the aluminum cover plate, aluminum foil, aluminum substrate and M metal foil with acetone, wipe them clean with anhydrous ethanol, and dry them in the air for later use.

5. The method for preparing a particle-reinforced aluminum-based composite material based on foil friction stir processing according to claim 1, characterized in that: In the stir friction processing of steps S3 and S4, the shoulder diameter of the stirring head is 15 to 22 mm, the stirring needle is conical, the root diameter of the stirring needle is 6 to 8 mm, the top diameter is 5 to 6 mm, the needle length is 1.8 to 5.5 mm, and the material of the stirring head is H13 tool steel or tungsten-rhenium alloy; the rotation speed of the stirring head during processing is 500 to 1400 r / min, the processing speed is 10 to 150 mm / min, the downward pressure is 0.02 to 0.2 mm, and the stirring head has no tilt angle.

6. The method for preparing a particle-reinforced aluminum-based composite material based on foil friction stir processing according to claim 1, characterized in that: During the friction stir processing in steps S3 and S4, argon gas is used as the protective atmosphere.

7. The method for preparing a particle-reinforced aluminum-based composite material based on foil friction stir processing according to claim 1, characterized in that: In step S3, a copper alloy or stainless steel pad with a thickness of 3 to 12 mm is placed between the processing unit and the workbench.

8. The method for preparing a particle-reinforced aluminum-based composite material based on foil friction stir processing according to claim 1, characterized in that: The method further includes repeating steps S3 and S4 to perform multiple friction stir processing processes to improve the uniformity of the particle reinforcement and reduce the size of the particles.

9. The method for preparing a particle-reinforced aluminum-based composite material based on foil friction stir processing according to claim 1, characterized in that: The method further includes step S5 of heat treating the prepared particle reinforced aluminum-based composite material plate.

10. A particle reinforced aluminum matrix composite material based on foil friction stir processing, characterized in that: The method is as described in any one of claims 1 to 9.

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