Aluminum alloy precise solid-state welding method based on vacuum hot pressing sintering process

Abstract

The invention relates to an aluminum alloy precise solid-state welding method based on a vacuum hot pressing sintering process. According to the method, Al powder, Mg powder, Si powder, Ti powder and Cu powder are mixed according to a certain proportion, then the mixed powder is subjected to cold press forming in advance, the influence caused by an oxidation film on the surface of the aluminum alloy is eliminated by means of elements such as Mg and Si in a vacuum environment, complex pretreatment does not need to be conducted on the aluminum alloy, and then solid-state precise welding of the aluminum alloy material is achieved. The method is easy and convenient to operate, and the requirement for aluminum alloy pre-welding pretreatment is low; in the welding process, base metal and mixed powder are both in a solid state, the welding temperature is low, the size precision is high, deformation is small, and the defect rate is low.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloy welding, and in particular to a precision solid-state welding method for aluminum alloy based on a vacuum hot pressing sintering process. Background Art

[0002] With the increasing requirements for materials in aerospace, automobile and other fields, the use of lightweight materials is of great significance. Aluminum alloys are widely used due to their advantages such as light weight, high strength and good corrosion resistance. Complex aluminum alloy components mainly use vacuum brazing and vacuum diffusion welding processes. However, due to the dense and stable oxide film on the surface of aluminum alloys, it is difficult to vacuum braze and diffuse weld aluminum and aluminum alloys. The brazing process is to heat the brazing material and the base material below the melting point of the weld to the welding temperature at the same time. After the brazing material is melted, the liquid brazing material fills the gap of the solid workpiece to connect the metals; when the brazing process is used to connect aluminum alloys, the brazing temperature is usually higher than 590℃, and the melting point of the brazing material used is about 530℃; but after the brazing material is melted, it is easy to have overburning and dissolution defects in the process of reaction with the base material, and the joint has poor precision and low dimensional qualification rate. Vacuum diffusion welding is a solid-phase connection process, the welding temperature is relatively low, and the dimensional accuracy of the joint is high.

[0003] CN 108453362 A discloses a method for direct diffusion welding assisted by surface activation of aluminum alloys. The method combines ion bombardment technology with diffusion welding technology to effectively remove surface oxide film and obtain welded joints with good structure and performance. However, the ion bombardment technology needs to be operated under vacuum, and the surface of the aluminum alloy is bombarded by introducing inert gas under the action of an electric field. The treatment process is relatively complex and has high requirements on equipment, resulting in high cost.

[0004] Vacuum diffusion welding has high requirements on the precision of aluminum alloy and the surface condition before welding, and often requires very complex aluminum alloy surface treatment process before welding. Summary of the invention

[0005] In view of the limitations of current technology, the present invention provides a precision solid-state welding method for aluminum alloys based on a vacuum hot pressing and sintering process. The method comprises the following steps: mixing Al, Mg, Si, Ti, and Cu powders in a certain proportion, and then pre-cold-pressing the mixed powders. In a vacuum environment, the influence of an oxide film on the surface of the aluminum alloy is eliminated by using elements such as Mg and Si. There is no need for complex pre-treatment such as surface activation of the aluminum alloy, thereby achieving solid-state precision welding of the aluminum alloy material, simplifying the connection process, and improving the dimensional accuracy of the welded structure.

[0006] The present invention is achieved through the following technical solutions: A method for precision solid-state welding of aluminum alloy based on vacuum hot pressing sintering process, the method comprising the following steps: (1) Place Al, Mg, Si, Ti and Cu powders into a ball mill and mill for 1-10 hours to obtain a mixed powder; In the mixed powder, the mass percentage of each component is Mg 0.1%-10%, Si 0.1%-13%, Ti 0%-3%, Cu 0%-4%, and the balance is aluminum; The Al, Mg, Si, Ti, and Cu powders have a particle size of 5-40 μm; The ball milling speed is 50-500 rpm, and the ball-to-material mass ratio is (25-5):1.

[0007] (2) mixing the obtained mixed powder with a binder in a mass ratio of (4-9):1, and mixing using a magnetic stirrer for 3-60 minutes to obtain a mixed powder slurry; The binder components are terpineol and polyethylene glycol, wherein the mass percentage of terpineol is 20-70%.

[0008] (3) Pour the obtained mixed powder slurry into a mold and dry it at 150°C-180°C for 2-3 hours to obtain a uniform mixed block after the binder evaporates; (4) The aluminum alloy substrate, the aluminum alloy cover plate and the mixed block obtained in step (4) are placed in a graphite mold for vacuum hot pressing and sintering to obtain an aluminum alloy joint.

[0009] The aluminum alloy is a 1 series aluminum alloy, a 2 series aluminum alloy, a 3 series aluminum alloy, a 5 series aluminum alloy, a 6 series aluminum alloy or a 7 series aluminum alloy; The aluminum alloy substrate and the aluminum alloy cover plate are aluminum alloys that are first surface pretreated and then dehydrated and degreased; The surface pretreatment includes machining, sandpaper grinding and polishing, including machining grooves, grinding with 400#, 800#, 1000#, 1500# and 2000# sandpapers in sequence and polishing, and the surface roughness Ra of the substrate and the cover plate is 1 to 3.2 μm; The surface degreasing and dehydration treatment is to use NaOH solution to clean the aluminum alloy, and then use acetone solution to perform ultrasonic cleaning on the substrate and cover plate for 5-10 minutes; The vacuum hot pressing sintering step comprises: S1: placing the aluminum alloy substrate at the bottom of a graphite mold; S2: placing the hybrid block in the aluminum alloy substrate slot; S3: Use a hydraulic press for cold pressing, the cold pressing pressure is 5-100MPa, and the time is maintained for 5-60min; S4: placing the aluminum alloy cover plate on top of the mixed block; S5: After cold pressing, vacuum hot pressing sintering is performed, and the vacuum degree during sintering is not less than 5×10 -3Pa, sintering temperature 540℃-620℃, sintering pressure 5-100MPa, holding time 0.5-5h; S6: After the insulation is completed, the temperature drops to 300℃-400℃ and then the pressure is released. The workpiece is taken out after cooling to room temperature.

[0010] The essential features of the present invention are: When brazing aluminum alloys are currently connected, the brazing temperature must be higher than the melting point of the brazing filler metal. After the brazing filler metal melts, it uses capillary action to fill the weld. During the reaction between the liquid brazing filler metal and the base material, the brazing filler metal can easily dissolve the aluminum alloy, resulting in poor dimensional accuracy and many defects after welding. In the present invention, the advantages of brazing and vacuum diffusion welding are fully combined, and the melting point of the mixed powder is made higher than the welding temperature by controlling the ratio of the mixed powder, thereby reducing the dissolution of the base material. The mixed powder is first pre-cold pressed, and the Mg and Si elements added to the powder under pressure break the oxide film on the surface of the aluminum alloy, eliminating the influence of the oxide film on the surface of the aluminum alloy; then during vacuum hot pressing sintering, the sintering temperature is in the range of 540℃-620℃. Since this range is lower than the melting point of the mixed powder, the mixed powder will not melt, thereby ensuring the dimensional accuracy of the joint after welding and realizing solid-state precision welding of aluminum alloy materials.

[0011] The beneficial effects of the present invention are: The aluminum alloy precision solid-state welding method based on vacuum hot pressing sintering process described in the present invention has the advantages of simple operation and low requirements for aluminum alloy pre-welding pretreatment; during the welding process, the base material and the mixed powder are both in a solid state, the welding temperature is low, the dimensional accuracy is high, the deformation is small and the defect rate is low. In the implementation case of the present invention, the dimensional deformation after welding is ≤0.03mm, and the welding rate is ≥90%; by applying a large pressure for sintering, the interface bonding is good (the tensile strength is increased by 12.3%); the powder material used does not contain precious metal materials, and the welding cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the aluminum alloy substrate in the present invention.

[0013] Figure 2 It is a schematic diagram of powder assembly of the present invention.

[0014] Figure 3 It is a schematic diagram of the sintering assembly of the present invention.

[0015] Figure 4 This is the backscattered image of the welding interface of Example 5.

[0016] In the figure: 1-mixed powder; 2-aluminum alloy substrate; 3-aluminum alloy cover plate; 4-upper pressure head; 5-graphite mold; 6-lower pressure head. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0018] The present invention provides an aluminum alloy precision solid-state welding method based on vacuum hot pressing sintering process, wherein the aluminum alloy substrate and the mixed powder are assembled as shown in FIG. Figure 2 As shown, the sintering assembly diagram is as follows Figure 3 shown.

[0019] The mixed powder 1 is placed in the groove of the aluminum alloy substrate 2, and the aluminum alloy cover plate 3 is placed on the upper part of the mixed powder, and they are assembled together into the graphite mold 5; the bottom of the graphite mold 5 is placed on the lower pressure head 6, and the upper pressure head 4 is directly in contact with the aluminum alloy cover plate 3; The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0020] Example 1 This embodiment provides an aluminum alloy precision solid-state welding method based on a vacuum hot pressing sintering process, and the aluminum alloy precision solid-state welding method comprises the following steps: (1) Select 60mm*60mm*8mm 1060 aluminum alloy as the aluminum alloy substrate base material, select 50mm*50mm*4mm 1060 aluminum alloy as the aluminum alloy cover base material, and process the 1060 aluminum alloy plate into Figure 1 The machined groove size is 50mm*50mm*6mm, and it is polished and polished with 400#, 800#, 1000#, 1500# and 2000# sandpaper in turn, so that the surface roughness Ra of the substrate groove is 1-3.2μm. The polished aluminum alloy plate is immersed in a 5% NaOH solution at a temperature of 50℃ for 1min, and then put into an acetone solution for ultrasonic cleaning for 10min.

[0021] (2) Place Al, Mg, Si, Ti, and Cu powders with a particle size of 15 μm in a ball mill at a mass ratio of Mg0.8%, Si10%, Ti0.15%, Cu0.2%, and the remainder Al, and ball mill at 200 rpm for 4 h. The ball-to-material mass ratio is 15:1. After mixing evenly, a mixed powder is obtained.

[0022] (3) The obtained mixed powder was mixed with a binder (pinene alcohol and polyethylene glycol; wherein the mass percentage of pinene alcohol is 25%) at a mass ratio of 8:1, and mixed using a magnetic stirrer for 30 min to obtain a mixed powder slurry. The slurry was then poured into a mold with a size of 50 mm*50 mm, and dried at 180°C for 2 h to obtain a mixed block with a size of 50 mm*50 mm*2 mm.

[0023] (4) Place the dried mixed block into the aluminum alloy substrate slot, apply a 10 MPa pressure to the powder using a press at room temperature for 30 min, then place the aluminum alloy cover plate on the top of the mixed powder and place it in a vacuum hot pressing sintering furnace for sintering. The vacuum degree during sintering is not less than 5×10 -3 Pa, the heating rate is 10℃ / min, the sintering temperature is 600℃, the sintering pressure is 10MPa, the holding time is 3h, the temperature is reduced to 400℃ and the pressure is released, and the workpiece is taken out after cooling to room temperature.

[0024] Example 2 This embodiment provides an aluminum alloy precision solid-state welding method based on a vacuum hot pressing sintering process, and the aluminum alloy precision solid-state welding method comprises the following steps: (1) Select 60mm*60mm*8mm 2024 aluminum alloy as the aluminum alloy substrate base material, select 50mm*50mm*4mm 2024 aluminum alloy as the aluminum alloy cover base material, and process the 2024 aluminum alloy plate into Figure 1 The machined groove size is 50mm*50mm*6mm, and it is polished and polished with 400#, 800#, 1000#, 1500# and 2000# sandpaper in turn, so that the surface roughness Ra of the substrate groove is 1-3.2μm. The polished aluminum alloy plate is immersed in a 5% NaOH solution at a temperature of 50℃ for 1min, and then put into an acetone solution for ultrasonic cleaning for 10min.

[0025] (2) Place Al, Mg, Si, Ti, and Cu powders with a particle size of 15 μm in a ball mill at a mass ratio of Mg 1.5%, Si 1%, Cu 4%, and the remainder Al, and ball mill at 300 rpm for 5 h. The ball-to-material mass ratio is 15:1. After mixing evenly, a mixed powder is obtained.

[0026] (3) The obtained mixed powder was mixed with a binder (pinene alcohol and polyethylene glycol; wherein the mass percentage of pinene alcohol is 55%) at a mass ratio of 6:1, and mixed using a magnetic stirrer for 30 min to obtain a mixed powder slurry, which was then poured into a mold with a size of 50 mm*50 mm and dried at 180°C for 2 h.

[0027] (4) Place the dried mixed block into the aluminum alloy substrate slot, apply a 5 MPa pressure to the powder using a press at room temperature for 50 min, then place the aluminum alloy cover plate on the top of the mixed powder and place it in a vacuum hot pressing sintering furnace for sintering. The vacuum degree during sintering is not less than 5×10 -3 Pa, the heating rate is 10℃ / min, the sintering temperature is 610℃, the sintering pressure is 40MPa, the holding time is 2h, the temperature is reduced to 400℃ and then the pressure is released, and the workpiece is taken out after cooling to room temperature.

[0028] Example 3 This embodiment provides an aluminum alloy precision solid-state welding method based on a vacuum hot pressing sintering process, and the aluminum alloy precision solid-state welding method comprises the following steps: (1) Select 60mm*60mm*8mm 3003 aluminum alloy as the aluminum alloy base plate parent material, select 50mm*50mm*4mm 3003 aluminum alloy as the aluminum alloy cover plate parent material, and process the 3003 aluminum alloy plate into Figure 1 The machined groove size is 50mm*50mm*6mm, and it is polished and polished with 400#, 800#, 1000#, 1500# and 2000# sandpaper in turn, so that the surface roughness Ra of the substrate groove is 1-3.2μm. The polished aluminum alloy plate is immersed in a 5% NaOH solution at a temperature of 50℃ for 1min, and then put into an acetone solution for ultrasonic cleaning for 10min.

[0029] (2) Place Al, Mg, Si, Ti, and Cu powders with a particle size of 20 μm in a ball mill at a mass ratio of Mg0.8%, Si10%, Ti0.15%, Cu0.2%, and the remainder Al, and ball mill at 300 rpm for 4 h. The ball-to-material mass ratio is 20:1, and then mix evenly to obtain a mixed powder.

[0030] (3) The obtained mixed powder was mixed with a binder (pinene alcohol and polyethylene glycol; wherein the mass percentage of pinene alcohol is 65%) at a mass ratio of 8:1, and mixed using a magnetic stirrer for 40 min to obtain a mixed powder slurry, which was then poured into a mold with a size of 50 mm*50 mm and dried at 180°C for 3 h.

[0031] (4) Place the dried mixed powder into the aluminum alloy substrate slot, apply a 10 MPa pressure to the powder using a press at room temperature for 30 min, then place the aluminum alloy cover plate on top of the mixed powder and place it in a vacuum hot pressing sintering furnace for sintering. The vacuum degree during sintering is not less than 5×10 -3 Pa, the heating rate is 10℃ / min, the sintering temperature is 620℃, the sintering pressure is 50MPa, the holding time is 1h, the temperature is reduced to 400℃ and then the pressure is released, and the workpiece is taken out after cooling to room temperature.

[0032] Example 4 This embodiment provides an aluminum alloy precision solid-state welding method based on a vacuum hot pressing sintering process, and the aluminum alloy precision solid-state welding method comprises the following steps: (1) Select 60mm*60mm*8mm 5052 aluminum alloy as the aluminum alloy base plate parent material, select 50mm*50mm*4mm 5052 aluminum alloy as the aluminum alloy cover plate parent material, and process the 5052 aluminum alloy plate into Figure 1The machined groove size is 50mm*50mm*6mm, and it is polished and polished with 400#, 800#, 1000#, 1500# and 2000# sandpaper in turn, so that the surface roughness Ra of the substrate groove is 1-3.2μm. The polished aluminum alloy plate is immersed in a 5% NaOH solution at a temperature of 50℃ for 1min, and then put into an acetone solution for ultrasonic cleaning for 10min.

[0033] (2) Place Al, Mg, Si, Ti, and Cu powders with a particle size of 30 μm in a ball mill at a mass ratio of Mg 2.5%, Si 10%, Ti 0.15%, Cu 0.1%, and the remainder Al, and ball mill at 400 rpm for 6 h. The ball-to-material mass ratio is 25:1. After mixing evenly, a mixed powder is obtained.

[0034] (3) The obtained mixed powder was mixed with a binder (pinene alcohol and polyethylene glycol; wherein the mass percentage of pinene alcohol is 50%) at a mass ratio of 8:1, and mixed using a magnetic stirrer for 30 min to obtain a mixed powder slurry, which was then poured into a mold with a size of 50 mm*50 mm and dried at 180°C for 2 h.

[0035] (4) Place the dried mixed block into the aluminum alloy substrate slot, apply a 10 MPa pressure to the powder using a press at room temperature for 30 min, then place the aluminum alloy cover plate on the top of the mixed powder and place it in a vacuum hot pressing sintering furnace for sintering. The vacuum degree during sintering is not less than 5×10 -3 Pa, the heating rate is 10℃ / min, the sintering temperature is 560℃, the sintering pressure is 40MPa, the holding time is 2h, the temperature is reduced to 400℃ and then the pressure is released, and the workpiece is taken out after cooling to room temperature.

[0036] Example 5 This embodiment provides an aluminum alloy precision solid-state welding method based on a vacuum hot pressing sintering process, and the aluminum alloy precision solid-state welding method comprises the following steps: (1) Select 60mm*60mm*8mm 6061 aluminum alloy as the aluminum alloy substrate base material, select 50mm*50mm*4mm 6061 aluminum alloy as the aluminum alloy cover base material, and process the 6061 aluminum alloy plate into Figure 1 The machined groove size is 50mm*50mm*6mm, and it is polished and polished with 400#, 800#, 1000#, 1500# and 2000# sandpaper in turn, so that the surface roughness Ra of the substrate groove is 1-3.2μm. The polished aluminum alloy plate is immersed in a 5% NaOH solution at a temperature of 50℃ for 1min, and then put into an acetone solution for ultrasonic cleaning for 10min.

[0037] (2) Place Al, Mg, Si, Ti, and Cu powders with a particle size of 15 μm in a ball mill at a mass ratio of Mg 1.2%, Si 12%, Ti 0.15%, Cu 0.15%, and the remainder Al, and mill at 400 rpm for 4 h. The ball-to-material mass ratio is 20:1. Mix well to obtain a mixed powder.

[0038] (3) The obtained mixed powder was mixed with a binder (pinene alcohol and polyethylene glycol; wherein the mass percentage of pinene alcohol is 50%) at a mass ratio of 9:1, and mixed using a magnetic stirrer for 30-50 min to obtain a mixed powder slurry, which was then poured into a mold of 50 mm*50 mm in size and dried at 180°C for 2 h.

[0039] (4) Place the dried mixed block into the aluminum alloy substrate slot, apply a 10 MPa pressure to the powder using a press at room temperature for 30 min, then place the aluminum alloy cover plate on the top of the mixed powder and place it in a vacuum hot pressing sintering furnace for sintering. The vacuum degree during sintering is not less than 5×10 -3 Pa, the heating rate is 10℃ / min, the sintering temperature is 580℃, the sintering pressure is 20MPa, the holding time is 2.5h, the temperature is reduced to 400℃ and then the pressure is released, and the workpiece is taken out after cooling to room temperature.

[0040] Example 6 This embodiment provides an aluminum alloy precision solid-state welding method based on a vacuum hot pressing sintering process, and the aluminum alloy precision solid-state welding method comprises the following steps: (1) Select 60mm*60mm*8mm 7A52 aluminum alloy as the aluminum alloy substrate base material, select 50mm*50mm*4mm 7A52 aluminum alloy as the aluminum alloy cover base material, and process the 7A52 aluminum alloy plate into Figure 1 The machined groove size is 50mm*50mm*6mm, and it is polished and polished with 400#, 800#, 1000#, 1500# and 2000# sandpaper in turn, so that the surface roughness Ra of the substrate groove is 1-3.2μm. The polished aluminum alloy plate is immersed in a 5% NaOH solution at a temperature of 50℃ for 1min, and then put into an acetone solution for ultrasonic cleaning for 10min.

[0041] (2) Place Al, Mg, Si, Ti, and Cu powders with a particle size of 15 μm in a ball mill at a mass ratio of Mg3%, Si12%, Ti0.2%, Cu0.2%, and the remainder Al, and mill at a speed of 400 rpm for 4 h. The ball-to-material mass ratio is 5:1, and then mix evenly to obtain a mixed powder.

[0042] (3) The obtained mixed powder was mixed with a binder (pinene alcohol and polyethylene glycol; wherein the mass percentage of pinene alcohol is 45%) at a mass ratio of 9:1, and mixed using a magnetic stirrer for 30-50 min to obtain a mixed powder slurry, which was then poured into a mold of 50 mm*50 mm in size and dried at 180°C for 2 h.

[0043] (4) Place the dried mixed block into the aluminum alloy substrate slot, apply a 10 MPa pressure to the powder using a press at room temperature for 30 min, then place the aluminum alloy cover plate on the top of the mixed powder and place it in a vacuum hot pressing sintering furnace for sintering. The vacuum degree during sintering is not less than 5×10 -3 Pa, the heating rate is 10℃ / min, the sintering temperature is 600℃, the sintering pressure is 5MPa, the holding time is 1h, the temperature is reduced to 400℃ and then the pressure is released, and the workpiece is taken out after cooling to room temperature.

[0044] The aluminum alloy welded by this method has small deformation of the base plate and good forming after welding. Figure 4 This is the backscattered image of the welding interface of Example 5. It can be seen that the 6061 aluminum alloy and the mixed powder are well combined, and no defects such as voids and cracks are found. The density is good after welding. The tensile strength of the welded joint is tested on an AGS-XD50kN universal testing machine according to GB / T 11363-2008 standard. Three samples are tested for each embodiment and the average value is taken. The shear strength of Example 5 reaches 155MPa. Compared with the patent CN 108453362 A indicating that the tensile strength of the 6061 aluminum alloy diffusion welded joint is 138MPa, this Example 5 is improved by 12.3%.

[0045] The applicant declares that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

[0046] Matters not covered by the present invention are known technologies.

Claims

1. A method for precision solid-state welding of aluminum alloy based on vacuum hot pressing sintering process, characterized in that the method comprises the following steps: (1) Place Al, Mg, Si, Ti and Cu powders into a ball mill and mill for 1-10 hours to obtain a mixed powder; In the mixed powder, the mass percentage of each component is Mg 0.1%-10%, Si 0.1%-13%, Ti 0%-3%, Cu 0%-4%, and the balance is aluminum; (2) mixing the obtained mixed powder with a binder in a mass ratio of (4-9):1, and mixing using a magnetic stirrer for 3-60 minutes to obtain a mixed powder slurry; The binder components are terpineol and polyethylene glycol; wherein, The mass percentage of terpineol is 20-70%; (3) pouring the obtained mixed powder slurry into a mold and drying it at 150°C-180°C for 2-3 hours to obtain a mixed block; (4) The aluminum alloy substrate, the aluminum alloy cover plate and the mixed block obtained in step (4) are placed in a graphite mold for vacuum hot pressing and sintering to obtain an aluminum alloy joint.

2. The aluminum alloy precision solid-state welding method based on vacuum hot pressing sintering process as claimed in claim 1, characterized in that The vacuum hot pressing sintering step comprises: S1: placing the aluminum alloy substrate at the bottom of a graphite mold; S2: placing the hybrid block in the aluminum alloy substrate slot; S3: Use a hydraulic press for cold pressing, the cold pressing pressure is 5-100MPa, and the time is maintained for 5-60min; S4: placing the aluminum alloy cover plate on top of the mixed block; S5: After cold pressing, vacuum hot pressing sintering is performed, and the vacuum degree during sintering is not less than 5×10 -3 Pa, sintering temperature 540℃-620℃, sintering pressure 5-100MPa, holding time 0.5-5h; S6: After the insulation is completed, the temperature drops to 300℃-400℃ and then the pressure is released. The workpiece is taken out after cooling to room temperature.

3. The aluminum alloy precision solid-state welding method based on vacuum hot pressing sintering process as described in claim 1, characterized in that the particle size of the Al, Mg, Si, Ti, and Cu powders is 5-40 μm.

4. The aluminum alloy precision solid-state welding method based on vacuum hot pressing sintering process as described in claim 1 is characterized in that the ball milling speed is 50-500 rpm and the ball-to-material mass ratio is (25-5):

1.

5. The aluminum alloy precision solid-state welding method based on vacuum hot pressing sintering process as claimed in claim 1, characterized in that The aluminum alloy is a 1 series aluminum alloy, a 2 series aluminum alloy, a 3 series aluminum alloy, a 5 series aluminum alloy, a 6 series aluminum alloy or a 7 series aluminum alloy.

6. The aluminum alloy precision solid-state welding method based on vacuum hot pressing sintering process as claimed in claim 1, characterized in that the aluminum alloy substrate and the aluminum alloy cover plate are aluminum alloys that are first surface pretreated and then dehydrated and degreased; The surface pretreatment includes machining, sandpaper grinding and polishing, including machining grooves, grinding with 400#, 800#, 1000#, 1500# and 2000# sandpapers in sequence and polishing, and the surface roughness Ra of the substrate and the cover plate is 1 to 3.2 μm; The surface degreasing and dehydration treatment is to use NaOH solution to clean the aluminum alloy, and then use acetone solution to perform ultrasonic cleaning on the substrate and the cover plate for 5-10 minutes.

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