Aluminum-based composite material-aluminum alloy connecting piece and friction stir forming method thereof

Abstract

The invention discloses an aluminum-based composite material-aluminum alloy connecting piece which comprises an aluminum-based composite material and aluminum alloy connected to one end of the aluminum-based composite material through friction stir welding. The aluminum-based composite material and the aluminum alloy are subjected to metallurgical bonding before friction stir welding, and a metallurgical bonding interface is formed at the bonding position of the aluminum-based composite material and the aluminum alloy; the invention further discloses a friction stir forming method of the aluminum-based composite material-aluminum alloy connecting piece, the method for connecting and forming the aluminum-based composite material and the dissimilar material is obtained in the mode that the procedures of casting, powder metallurgy, friction stir machining and the like are combined, and the problem that the aluminum-based composite material and the dissimilar metal material are difficult to connect is solved. The reliability of connection forming of the aluminum-based composite material and the dissimilar metal is improved, the service safety of the aluminum-based composite material and the dissimilar metal material under the high-low temperature alternating condition is improved, and meanwhile the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of material forming technology, specifically to an aluminum-based composite material-aluminum alloy connector and its friction stir forming method. Background Technology

[0002] Aluminum-based composites possess characteristics such as lightweight, high strength, high wear resistance, high modulus, high thermal conductivity, and low expansion, making them promising for applications in vehicle braking and electronic packaging. However, the addition of reinforcing ceramic particles worsens the molding processability of aluminum-based composites; the higher the content of reinforcing particles, the more difficult it is to mold complex products. To meet the functional requirements of products, some products require the use of aluminum-based composites in specific areas. Existing connection methods mainly include brazing, bolting, and laser welding, but each has its drawbacks. When brazing aluminum-based composites to dissimilar materials, the brazing filler metal diffuses to a relatively shallow depth between the aluminum-based composite and the dissimilar material, resulting in significant differences in internal structure at the joint and lower shear strength. Under alternating thermal loads, the difference in linear expansion coefficients leads to higher internal stress, making the joint prone to failure. When bolts are used for fastening, under alternating high-temperature loads, the difference in the coefficient of linear expansion between aluminum-based composites and dissimilar materials causes the bolts to bear significant tensile or shear stresses during expansion. Aluminum-based composites soften easily at high temperatures, and when they interact with the bolts, indentations are easily formed. These indentations cannot recover after the temperature drops, leading to loosening of the fasteners. When using laser or other fusion welding methods, the weldability of aluminum-based composites is poor, easily resulting in defects such as porosity. At high temperatures, the aluminum alloy matrix readily reacts with SiC particles to form a brittle and hard Al₄C₃ phase, affecting the material's service performance.

[0003] Because the metallurgical bonding layer between aluminum-based composites and aluminum alloys is relatively thin, they are prone to failure under high shear forces. Furthermore, due to the difference in the coefficients of linear expansion between aluminum-based composites and cast aluminum alloys, they are susceptible to failure under alternating stresses at high and low temperatures. Therefore, increasing the thickness of the metallurgical bonding layer at the joint is a pressing technical problem that needs to be solved. Summary of the Invention

[0004] This invention designs and develops a friction stir forming method for aluminum-based composite materials and aluminum alloy connectors. This invention combines casting, powder metallurgy, and friction stir forming processes to obtain a method for joining aluminum-based composite materials with dissimilar materials, solving the problem of difficult joining aluminum-based composite materials with dissimilar metal materials, improving the reliability of joining aluminum-based composite materials with dissimilar metals, and reducing production costs.

[0005] This invention designs and develops an aluminum-based composite material-aluminum alloy connector, which solves the problems of low connection strength and poor connection reliability of existing aluminum-based composite materials and aluminum alloys.

[0006] The technical solution provided by this invention is as follows: An aluminum-based composite material-aluminum alloy connector includes: an aluminum-based composite material and an aluminum alloy connected to one end of the aluminum-based composite material by friction stir welding; Before friction stir welding, the aluminum-based composite material and the aluminum alloy are first metallurgically bonded, and a metallurgical bonding interface is formed at the bonding point between the aluminum-based composite material and the aluminum alloy.

[0007] Preferably, the grain size of the weld joint area between the aluminum-based composite material and the aluminum alloy is refined to 1-10 μm, and the elongation is 2-8%.

[0008] Preferably, the depth of the bonding layer at the metallurgical interface is 3-8 mm.

[0009] Preferably, the aluminum-based composite material is a silicon carbide powder reinforced aluminum-based composite material; The proportion of silicon carbide powder is 30%-60% by mass.

[0010] Preferably, the aluminum alloy is a ZL101A material alloy.

[0011] A friction stir forming method for aluminum-based composite materials-aluminum alloy connectors includes the following steps: Step 1: Place the aluminum-based composite material into the mold for aluminum alloy casting. After filling, quickly increase the pressure to solidify the joint between the aluminum-based composite material and the aluminum alloy under the increased pressure. Step 2: Remove the casting and fix it on the friction stir test table to perform friction stir welding to obtain an aluminum-based composite material-aluminum alloy connector; wherein, the feed speed of friction stir welding is set to 200-350mm / min, the rotation speed is 1000-1200r / min, and the indentation is 0.2-0.3mm.

[0012] Preferably, in step one, the instantaneous contact temperature of the aluminum-based composite material with the molten aluminum alloy is controlled between 670-700°C; and The casting temperature is controlled at 700-720℃.

[0013] Preferably, in step one, the filling pressure is 0.03-0.04 MPa and the boosting pressure is 0.06-0.07 MPa.

[0014] Preferably, in step one, after the aluminum alloy casting is held for 2 seconds, the mold pressure is increased to the filling pressure for 1 second, held for 2 seconds, and then increased to the boost pressure for 4 seconds, and finally returned to normal pressure.

[0015] Preferably, in step two, friction stir welding is performed to cover the joint between the aluminum-based composite material and the aluminum alloy in one, multiple, or complete manner.

[0016] The beneficial effects of this invention are as follows: 1. The friction stir forming method for aluminum-based composite material-aluminum alloy connectors provided by the present invention successfully realizes the connection between aluminum-based composite material and aluminum alloy, and solves the difficult process problem of connecting aluminum-based composite material and aluminum alloy by combining casting and friction stir welding. 2. The friction stir forming method for aluminum-based composite material-aluminum alloy connectors provided by this invention enables the aluminum-based composite material and aluminum alloy to fuse together at the connection point, with a mutual penetration depth of 3-10 mm, resulting in a strong bond. The content of reinforcing particles at the connection point achieves a gradient change from aluminum-based composite material to aluminum alloy, and the average grain size at the connection point is refined from the original 60-80 μm to 1-10 μm. The elongation is increased from 0.5%-2% to 2%-8%, significantly improving fatigue resistance. At the same time, the core of the connection part has a low coefficient of thermal expansion, while the outer part has a high coefficient of thermal expansion, which can alleviate the stress generated by the difference in linear expansion between the two materials under thermal fatigue conditions, ensuring the reliability of the two materials during service after connection. 3. The aluminum-based composite material-aluminum alloy connector provided by this invention breaks through the limitations of material connection technology, can form a variety of complex products, and realize the use of materials with different properties in different parts of the product, making full use of materials and further expanding the application range of aluminum-based composite materials and other light alloys. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the powder metallurgy preparation of aluminum-based composite materials according to the present invention; Figure 2 This is a schematic diagram of the pressure casting process for preparing aluminum-based composite materials according to the present invention; Figure 3 This is a schematic diagram of the pressure casting curve described in this invention; Figure 4 This is a schematic diagram of the aluminum-based composite material after casting according to the present invention; Figure 5 This is a schematic diagram of friction stir welding as described in this invention; Figure 6 This is a schematic diagram of the composite material-aluminum alloy connector after stirring friction according to the present invention; Figure 7a This is a microstructure diagram showing the poor bonding between the casting aluminum-based composite material and the aluminum alloy interface described in this invention. Figure 7b This is a microstructure diagram of the interface after stirring and rubbing the poorly bonded area as described in this invention; Figure 8aThis is a microstructure diagram of the interface between the cast aluminum-based composite material and the aluminum alloy as described in this invention, showing a good bond. Figure 8b This is a microstructure diagram of the well-bonded interface after stirring and friction, as described in this invention. Figure 9 This is a magnified image of the microstructure at the interface after stirring and friction as described in this invention. Figure 10a Metallographic photograph of the aluminum-based composite material described in this invention before stirring and friction; Figure 10b This is an electron backscattering diffraction pattern of the aluminum-based composite material after stirring and friction according to the present invention; Figure 11a This is a macroscopic morphology diagram of the metallurgical bonding surface before the stirring friction described in this invention; Figure 11b This is a macroscopic morphology diagram of the metallurgical bonding surface after stirring and friction as described in this invention. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0019] This invention provides a method for connecting aluminum-based composite materials and aluminum alloy connectors, comprising the following steps: Step 1: Preparation of aluminum-based composite materials: Step 1: Select SiC powder with an average size of 10-50μm and bake the SiC powder at a high temperature of 1000-1200℃. Stir the powder every half hour during baking to form an SiO2 oxide film on the surface of the SiC. Step 2: Select aluminum alloy powder with a diameter of 2-10μm as raw material, and mix the aluminum alloy powder and SiC thoroughly by ball milling at a speed of 30r / min to 60r / min for 1h to 2h. The aluminum alloy powder consists of 1-2 wt% Cu powder, 0.8-1 wt% Mg powder, 2-3 wt% Si powder, 0.5 wt% Ti powder, 0.2 wt% Sn powder, and the balance Al powder; the SiC content is 30%-60% by mass. Step 3: The mixed powder is cold-pressed and degassed, sintered at 500-600℃ for 2 hours, and then hot-pressed to form a compact; Step 4: Extrude the compact at 400-500℃ at an extrusion ratio of 7:1 into an aluminum-based composite material sheet with a thickness of 20mm. Step 5: After milling / grinding one side of the aluminum-based composite material sheet, clean and dry it for later use. Step 2: Pressure casting: Step 1: Use ZL101A alloy material, dry it, and melt it at 750℃; Step 2: After the alloy has completely melted, add the AL-Cu master alloy to make the Cu content of the aluminum alloy liquid reach 2%-3.5% by mass. Step 3: Add Sr modifier and refining agent, and at the same time, argon gas is introduced into the aluminum liquid for degassing and refining to remove water vapor and inclusions in the melt, so that the melt is effectively purified. The degassing and refining time is 15-30 minutes. Step 4, as follows Figure 2 As shown, the aluminum-based composite material is placed into the cavity of the casting mold and fixed, and then the mold is closed; Step 5, as follows Figure 3 As shown, casting is carried out at 700-720℃ with a filling pressure of 0.03-0.04 MPa. After filling, the pressure is rapidly increased to 0.06-0.07 MPa to improve the density of the aluminum alloy casting. In this process, after holding the aluminum alloy casting pressure for 2 seconds, the mold pressure is increased to the filling pressure for 1 second, held for 2 seconds, and then increased to the boost pressure for 1 second, held for 4 seconds, and finally returned to normal pressure. Step 6: Open the mold, remove the casting, and remove the gating and risers, as shown. Figure 4 As shown, a casting with aluminum-based composite material 110 on one side and aluminum alloy 120 on the other side is obtained. The aluminum-based composite material 110 and aluminum alloy 120 are fused together at the joint to form a metallurgical bonding interface 130a. Step 3: Preparation of aluminum-based composite materials – aluminum alloy connectors – by friction stir: like Figure 5 , Figure 6 As shown, the aluminum-based composite material workpiece is fixed on the worktable of the friction stir test, and friction stir welding is performed along the bonding surface by friction stir. The feed rate for friction stir welding is 200-350 mm / min, the rotation speed is 1000-1200 r / min, and the indentation is 0.2-0.3 mm. Step 4: Heat treatment: T6 heat treatment is applied to aluminum matrix composite parts after friction stir welding to improve the strength and hardness of the products. Step 5: Processing to obtain aluminum-based composite material - aluminum alloy connector: The heat-treated aluminum-based composite material product is processed to the required size to obtain an aluminum-based composite material-aluminum alloy connector.

[0020] The present invention also provides an aluminum-based composite material-aluminum alloy connector, such as... Figure 1As shown, the aluminum-based composite material 110 welding section forms a prominent bevel. The bevel shape is either a regular or inverted trapezoid to increase the contact area with the aluminum alloy. At the same time, the aluminum-based composite material and the aluminum alloy interlock to prevent the aluminum-based composite material and the aluminum alloy material from sliding against each other in the X direction. As a preferred option, the bevel shape can be formed by milling / grinding or directly formed during the early extrusion process.

[0021] In another embodiment, such as Figure 2 As shown, the casting mold is composed of multiple spliced ​​pieces, including multiple splicing seams 211 and 212, a casting aluminum alloy cavity 210, an ingate 220, and a sprue 230. The splicing seams 211 and 212 are set at the highest point of the cavity. Several venting seams with a width of 10 mm and a thickness of 0.2 mm are set on the splicing seams 211 and 212 to facilitate the removal of air from the casting aluminum alloy cavity 210 during filling and to prevent defects such as porosity. The casting mold is baked to 300°C, then a release agent is sprayed on it, and then it is dried.

[0022] In another embodiment, such as Figure 4 As shown, the metallurgical interface 130a between the aluminum-based composite material 110 and the aluminum alloy 120 solidifies under pressure, resulting in finer grains and improved bonding strength. The liquidus temperature of ZL101A is approximately 615℃. During the casting process, the instantaneous temperature of the contact surface between the aluminum-based composite material and the cast aluminum alloy solution is controlled between 670-700℃, so a thin molten layer forms on the surface of the aluminum-based composite material. After cooling, the contact surface between the aluminum-based composite material 110 and the cast aluminum alloy 120 achieves metallurgical bonding.

[0023] In another embodiment, such as Figure 4 As shown, the aluminum-based composite material 110 and the aluminum alloy 120 are fused together to form a metallurgical bonding interface 130a. The bonding layer of the metallurgical bonding interface 130a has a depth of 1-2 mm. This bonding interface can withstand certain shear forces and stress caused by different thermal expansion under alternating high and low temperature conditions, but it is prone to failure if the temperature is too high.

[0024] In another embodiment, because the metallurgical bonding layer between the aluminum-based composite material and the aluminum alloy is relatively thin, it is prone to failure under large shear forces. Furthermore, due to the difference in the coefficients of linear expansion between the aluminum-based composite material and the cast aluminum alloy, failure is likely to occur under alternating stress at high and low temperatures. Therefore, it is necessary to increase the thickness of the metallurgical bonding layer at the joint. As a preferred embodiment, such as... Figure 6As shown, the grain size of the 130b cast aluminum alloy in the weld joint region of friction stir welding is refined, with the average grain size decreasing from 60-80 μm to 1-10 μm, and the elongation increasing from 2% to 8%, exhibiting good fatigue resistance. The grain size of the aluminum-based composite material in the 130b weld joint region of friction stir welding is also refined, with a more uniform SiC distribution, effectively improving the material's fatigue resistance. The aluminum-based composite material and aluminum alloy are mixed within the joint region, increasing the thickness of the metallurgical region from 1-2 mm to 3-8 mm, effectively enhancing the material's bonding strength. When the temperature rises, the core aluminum-based composite material in the joint has a low coefficient of linear expansion, while the outer aluminum alloy has a higher coefficient of linear expansion. This reduces the stress caused by the difference in the coefficient of linear expansion of the outer material under alternating hot and cold temperatures, lowering the risk of failure.

[0025] In another embodiment, friction stir welding is performed along the mating surface by means of friction stir. The friction stir weld can be a single weld or can completely cover the bevel area. The number of friction stir welds mainly depends on the service conditions of the workpiece. The more welds there are, the wider the coverage area and the better the bonding force, but it will increase the production cost. Therefore, the number of friction stir welds needs to take into account both the bonding force and the production cost.

[0026] In another embodiment, the aluminum-based composite material sheet can be prepared by stir casting or pressure impregnation; the aluminum alloy material can be aluminum-copper or other alloys, and the aluminum alloy side can be a sheet or other shaped products, such as brake discs, heat dissipation devices, etc.

[0027] The present invention will be further described below with reference to specific embodiments and test examples.

[0028] Example This invention provides a method for connecting aluminum-based composite materials and aluminum alloy connectors, comprising the following steps: Step 1: Preparation of aluminum-based composite materials: Step 1: Select SiC powder with an average size of 10-50μm and bake the SiC powder at a high temperature of 1100℃. Stir it every half hour during baking to form an SiO2 oxide film on the surface of SiC. Step 2: Select aluminum alloy powder with a diameter of 2-10μm as raw material, and mix the aluminum alloy powder and SiC thoroughly by ball milling at a speed of 60r / min for 1 hour. The aluminum alloy powder consists of 2 wt% Cu powder, 0.8 wt% Mg powder, 2 wt% Si powder, 0.5 wt% Ti powder, 0.2 wt% Sn powder, and the balance Al powder; the SiC content is 35% by mass. Step 3: The mixed powder is cold-pressed, degassed, sintered at 500-600℃ for 2 h, and then hot-pressed to form a compact; Step 4: Extrude the compact at 400-500℃ at an extrusion ratio of 7:1 into an aluminum-based composite material sheet with a thickness of 20mm. Step 5: After milling / grinding one side of the aluminum-based composite material sheet, clean and dry it for later use. Step 2: Pressure casting: Step 1: Use ZL101A alloy material, dry it, and melt it at 750℃; Step 2: After the alloy has completely melted, add the AL-Cu master alloy so that the Cu content in the molten aluminum alloy reaches the theoretical mass fraction of 2%. Step 3: Add Sr modifier and refining agent, and at the same time, argon gas is introduced into the aluminum liquid for degassing and refining to remove water vapor and inclusions in the melt, so that the melt is effectively purified. The degassing and refining time is 15-30 minutes. Step 4, as follows Figure 2 As shown, the aluminum-based composite material is placed into the cavity of the casting mold and fixed, and then the mold is closed; Step 5, as follows Figure 3 As shown, casting is carried out at 700-720℃, and the filling pressure is set to 0.03 MPa. After filling is completed, the pressure is rapidly increased to 0.07 MPa to improve the density of the aluminum alloy casting. In this process, after the aluminum alloy casting is held for 2 seconds, the mold pressure is increased to the filling pressure for 1 second, held for 2 seconds, and then increased to the boost pressure for 1 second, held for 4 seconds, and finally returned to normal pressure.

[0029] Step 6: Open the mold, remove the casting, and remove the gating and risers, as shown. Figure 4 As shown, a casting with aluminum-based composite material 110 on one side and aluminum alloy 120 on the other side is obtained. The aluminum-based composite material 110 and aluminum alloy 120 are fused together at the joint to form a metallurgical bonding interface 130a. Step 3: Preparation of aluminum-based composite materials – aluminum alloy connectors – by friction stir: like Figure 5 , Figure 6 As shown, the aluminum-based composite material workpiece is fixed on the worktable of the friction stir test, and friction stir welding is performed along the bonding surface by friction stir. The feed rate for friction stir welding is 200-350 mm / min, the rotation speed is 1000-1200 r / min, and the indentation is 0.2 mm. Step 4: Heat treatment: T6 heat treatment is applied to aluminum matrix composite parts after friction stir welding to improve the strength and hardness of the products. Step 5: Processing to obtain aluminum-based composite material - aluminum alloy connector: The heat-treated aluminum-based composite material product is processed to the required size to obtain the aluminum-based composite material product.

[0030] Test case Metallographic specimens measuring 15mm × 15mm × 20mm were cut from the friction stir joint area using a wire EDM machine. After grinding and polishing, the specimens were etched with a 0.5% (v / v) hydrofluoric acid aqueous solution for 5–10 s, and the microstructure was observed using a Leica-DM6000M metallographic microscope. The grain size of the composite material was analyzed using a scanning electron microscope (SEM, Zeiss Sigma 500) equipped with electron backscatter diffraction (EBSD) technology.

[0031] According to GB / T 13683-1992, shear test method, a CMT 5504 microcomputer-controlled electronic universal testing machine (FM-028) was used to conduct shear tests on the connection between aluminum matrix composites and aluminum alloys.

[0032] According to the test method of GB / T 228.1—2021, room temperature tensile tests were conducted using a CMT5504 microcomputer-controlled electronic universal testing machine.

[0033] Performance tests were conducted on the above embodiments, and the results are as follows: like Figure 7a As shown, there are obvious gap defects at the interface between the aluminum-based composite material and the aluminum alloy. The presence of these defects will affect the service performance of the material. Figure 7b As shown, the interface defects have been eliminated; Figure 7a , 7b As shown, after direct casting, unfusion defects are easily generated at the interface between aluminum alloy and aluminum-based composite material. The bonding strength of the unfused parts is low, and they are prone to failure during service. The unfusion defects are eliminated after stirring and friction.

[0034] like Figure 8a As shown, there are no obvious interface defects in the aluminum-based composite material and aluminum alloy material at the joint. However, due to the influence of heat input, the grains of both materials become coarse, affecting their service performance. Figure 8b As shown, the composite material and aluminum alloy layer are well bonded, and the coarse microstructure is refined. This refined microstructure improves the material's service performance. Figure 8a , Figure 8b , Figure 9As shown, in areas where the inlay is well fused, the aluminum alloy grains reach the silicon phase, which is arranged in a grid pattern and some are elongated. After stirring and friction, the aluminum alloy grains are refined, and the silicon phase becomes small spheres that are evenly distributed, which improves the elongation of the material and also improves its fatigue resistance.

[0035] After friction stirring, the shear strength of the connection between the aluminum matrix composite and the aluminum alloy is 153 MPa, while after direct casting, the shear strength of the connection between the aluminum matrix composite and the aluminum alloy is 82 MPa.

[0036] like Figure 10a As shown, metallographic analysis was performed on the unstirred aluminum-based composite material. The metallographic image showed a grain size of 60-80 micrometers, with SiC particles mainly distributed at the grain boundaries. Because the composite material after stirring and friction has fine grains, the metallographic image could not clearly reveal the grain size. Electron backscatter diffraction (EBSD) was used for grain size analysis, as shown... Figure 10b As shown, the composite material grains after friction stir are approximately 1-10 μm; the grains of the 130b cast aluminum alloy in the weld joint area of ​​friction stir welding are refined, the SiC distribution is more uniform, the average grain size is refined from 60-80 μm to 1-10 μm, and the elongation is increased from 2% to 8%. Tensile specimens and hardness samples were prepared in the weld joint area of ​​friction stir welding, and the elongation was up to 8%, indicating good fatigue resistance.

[0037] like Figure 11a As shown, from the macroscopic morphology of the joint before friction stirring, the casting-metallurgical interface is relatively straight, and the boundary between the composite material and the aluminum alloy is relatively clear; the metallurgical region is about 1-2 mm, such as... Figure 11b As shown, after stirring and friction, the aluminum-based composite material and aluminum alloy are mixed together in the bonding area, and the thickness of the metallurgical area is increased from 1-2mm to 3-8mm, which effectively improves the bonding strength of the materials.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An aluminum-based composite material-aluminum alloy connector, characterized in that, include: Aluminum-based composite material and aluminum alloy connected to one end of the aluminum-based composite material by friction stir welding; Before friction stir welding, the aluminum-based composite material and the aluminum alloy are first metallurgically bonded, and a metallurgical bonding interface is formed at the bonding point between the aluminum-based composite material and the aluminum alloy.

2. The aluminum-based composite material-aluminum alloy connector as described in claim 1, characterized in that, The grain size of the weld joint area between the aluminum-based composite material and the aluminum alloy is refined to 1-10 μm, and the elongation is 2-8%.

3. The aluminum-based composite material-aluminum alloy connector as described in claim 1 or 2, characterized in that, The depth of the bonding layer at the metallurgical interface is 3-8 mm.

4. The aluminum-based composite material-aluminum alloy connector as described in claim 3, characterized in that, The aluminum-based composite material is a silicon carbide powder reinforced aluminum-based composite material; The proportion of silicon carbide powder is 30%-60% by mass.

5. The aluminum-based composite material-aluminum alloy connector as described in claim 3, characterized in that, The aluminum alloy is ZL101A material alloy.

6. A method for friction stirring forming of aluminum-based composite materials-aluminum alloy connectors, characterized in that, Includes the following steps: Step 1: Place the aluminum-based composite material into the mold for aluminum alloy casting. After filling, quickly increase the pressure to solidify the joint between the aluminum-based composite material and the aluminum alloy under the increased pressure. Step 2: Remove the casting and fix it on the friction stir test table to perform friction stir welding to obtain an aluminum-based composite material-aluminum alloy connector; wherein, the feed speed of friction stir welding is set to 200-350mm / min, the rotation speed is 1000-1200r / min, and the indentation is 0.2-0.3mm.

7. The friction stir forming method for aluminum-based composite materials-aluminum alloy connectors as described in claim 6, characterized in that, In step one, the instantaneous temperature of the contact surface between the aluminum-based composite material and the molten aluminum alloy is controlled between 670-700℃; and The casting temperature is controlled at 700-720℃.

8. The friction stir forming method for aluminum-based composite materials-aluminum alloy connectors as described in claim 6 or 7, characterized in that, In step one, the filling pressure is 0.03-0.04 MPa and the pressurization pressure is 0.06-0.07 MPa.

9. The friction stir forming method for aluminum-based composite materials-aluminum alloy connectors as described in claim 8, characterized in that, In step one, after the aluminum alloy casting is held for 2 seconds, the mold pressure is increased to the filling pressure for 1 second, held for 2 seconds, and then increased to the boost pressure for 4 seconds. Finally, the pressure is restored to normal pressure.

10. The friction stir forming method for aluminum-based composite materials-aluminum alloy connectors as described in claim 8, characterized in that, In step two, friction stir welding is performed to cover the joint between the aluminum-based composite material and the aluminum alloy in one, multiple, or complete manner.

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