Diffusion bonding method for diffusion compounding of aluminum alloy / titanium alloy net material

Abstract

The invention discloses a diffusion bonding method for diffusion compounding of an aluminum alloy / titanium alloy net material, and belongs to the field of diffusion bonding. According to the embodiment, the problem that when an existing diffusion bonding method is used for preparing the metal composite structure, the diffusion time needed for achieving high-strength bonding is extremely long is solved. A layer of compact and uniform copper film is prepared on the surface of the titanium alloy net material through the electro-deposition process, a copper coating film is formed to serve as a diffusion connection middle layer, and then the aluminum alloy plate and the titanium alloy net material are subjected to plastic deformation through the rolling process so that diffusion connection can be rapidly conducted on the plate and the net material to achieve dissimilar metal connection. Therefore, the problem of extremely slow diffusion of solid atoms in a traditional diffusion bonding process is avoided, and the production efficiency of diffusion bonding of dissimilar metals is greatly improved. The method is suitable for connection of a plate / net material composite structural part with a complex geometrical shape and a large-area and large-thickness component, so that the mechanical property of the composite structural part is further improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of diffusion bonding, and particularly relates to a diffusion bonding method for diffusion composite of aluminum alloy / titanium alloy mesh materials. BACKGROUND

[0002] Superplastic forming / diffusion bonding (SPF / DB) is an advanced light-weight forming technology, which has the advantages of low cost, simple operation and small forming pressure. The formed parts have accurate size, stable performance, no obvious weld and no residual stress. The combination of the two technologies for forming complex-shaped parts utilizes the advantages of both and has the advantages of high strength and light weight, and has been widely used in the aerospace, automobile and electronic industries.

[0003] Aluminum alloy has the advantages of low price, low density, high stiffness-to-weight ratio and good superplasticity; titanium alloy has the characteristics of low density, high strength and strong resistance to high-temperature impact, but the difficulty in extracting titanium element limits its application range. Aluminum alloy / titanium alloy mesh composite material fully cooperates the advantages of component metals and becomes a new type of material with the advantages of light weight, high strength and good superplasticity. However, the properties of titanium / aluminum alloy are quite different, and the solid solubility between them is small, so the composite structure is difficult to prepare, and the composite mechanism is complex, so the requirements for the material composite process are more stringent.

[0004] Traditional diffusion bonding is a precise bonding method in which metal layers are not only connected tightly but also plastically deformed under a relatively low temperature and a large pressure, and the deformed metal atoms diffuse into each other to form a new diffusion layer and thus form a reliable connection. First, due to the limitation of equipment, the traditional diffusion bonding process can only prepare small-sized composite plates; second, brittle intermetallic compounds exist in the preparation process of aluminum-titanium composite plates, which leads to the fact that the diffusion bonding method is rarely applied in the preparation and production of aluminum-titanium composite plates; third, the atomic diffusion speed is extremely slow in the solid state, and a long diffusion time is required to achieve a high-strength bond at the interface of the metal composite structure prepared by the traditional diffusion bonding process, so the process cycle of the traditional diffusion bonding process for preparing the metal composite structure is generally long.

[0005] Rolling is a promising heterogeneous metal bonding technology. The principle is to use the rolling force generated by the rolling mill to make the metal produce large deformation and thus rapidly diffuse and bond under high temperature conditions. Compared with the traditional diffusion bonding method, the rolling method requires relatively small rolling pressure and short welding time, and greatly improves the production efficiency. SUMMARY

[0006] The application provides a diffusion connection method for diffusion composite of aluminum alloy / titanium alloy mesh materials in order to solve the problems of low efficiency and long process period in the traditional diffusion connection process of dissimilar metal composite materials.

[0007] A diffusion connection method for diffusion composite of aluminum alloy / titanium alloy mesh materials, and the method is completed according to the following steps:

[0008] I. The aluminum alloy plate is polished to be flat, surface oil stains are removed, cleaned, and dried to obtain the pretreated aluminum alloy plate;

[0009] II. The titanium alloy mesh material is polished to be flat, surface oil stains are removed, cleaned, and dried to obtain the pretreated titanium alloy mesh material;

[0010] III. A uniform copper film is deposited on the surface of the pretreated titanium alloy mesh material by using an electrodeposition process to obtain the titanium alloy mesh material with the copper film on the surface;

[0011] IV. A piece of the titanium alloy mesh material with the copper film on the surface is arranged between two pieces of the pretreated aluminum alloy plate, then rivets are used for fixation, an isolating agent is sprayed, and the titanium alloy mesh material is placed in a package;

[0012] V. A gas pipe is arranged at the opening of the package, and the package and the gas pipe are welded to seal the package to become the material to be rolled;

[0013] VI. The material to be rolled is vacuumized through the external gas pipe;

[0014] VII. The vacuumized material to be rolled is placed in a high-temperature furnace which is heated to the diffusion connection temperature, and the material to be rolled is kept for a period of time to obtain the material to be rolled;

[0015] VIII. The material to be rolled is taken out from the high-temperature furnace and quickly placed in a rolling mill for rolling, and then quickly placed in cold water for cooling after the rolling is completed;

[0016] IX. After the rolling is completed, the air supply and the vacuumization are stopped;

[0017] X. The material after rolling is cut by a wire cutting machine to obtain the aluminum alloy / titanium alloy mesh material diffusion composite structure.

[0018] The application has the following advantages:

[0019] The application provides a method for quickly realizing diffusion composite of aluminum alloy / titanium alloy mesh materials by using rolling, and the method can successfully realize rapid forming of the aluminum alloy / titanium alloy mesh material diffusion composite structure parts, and the interface bonding strength of the composite structure formed by the method is high.

[0020] (1), the first stage of the method provided by the application is a copper plating stage of the titanium alloy mesh material, metal copper is electroplated on the titanium alloy mesh material by using an electrodeposition method, a uniform metal plating layer is formed, eutectic reaction can occur with the plate to promote subsequent diffusion connection, and process parameters are reduced;

[0021] (2), the second stage of the method provided by the application is a rolling stage, at this time, under the action of the rolling pressure of the rolling mill, the plate and the mesh material are plastically deformed and rapidly diffusion connected to realize the forming process of dissimilar metal connection, the post-welding organization and performance are uniform, and the interface bonding strength of the rolling connection is high;

[0022] (3), in the rolling stage, the rolling connection process is used, compared with the existing traditional diffusion connection process, the welding time is short because the long metal diffusion process is not needed, and the production efficiency is greatly improved;

[0023] (4), in the rolling stage, compared with the existing traditional diffusion connection process, brittle intermetallic compounds are not generated, and brittle fracture is not prone to occur;

[0024] (5), the application is suitable for connecting plate / mesh composite structure parts with complex geometric shapes and large-area and large-thickness components; the organization of the composite structure can be regulated by controlling the rolling temperature and the reduction in the rolling stage, so that the mechanical properties of the composite structure part are further improved. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a forming process schematic diagram of example 1;

[0026] Figure 2 It is a separator spraying schematic diagram of example 1;

[0027] Figure 3 It is a digital photo of a three-layer composite structure formed in example 1;

[0028] Figure 4 It is a tensile property comparison diagram of parts formed in example 1 and comparative example 1;

[0029] In the drawing, 1 is a plate, 1-1 is an upper aluminum alloy plate, 1-2 is a lower aluminum alloy plate, 2 is a titanium alloy mesh material, 3 is a sleeve, 4 is a rivet, and 5 is an air pipe. DETAILED DESCRIPTION

[0030] In the following description, many specific details are set forth in order to provide a thorough understanding of the application, but the application can be practiced without the specific details, which are not described in the description, and the person skilled in the art can make similar generalizations without departing from the concept of the application, therefore, the application is not limited by the specific examples disclosed below.

[0031] Specific embodiment one: the diffusion bonding method of the aluminum alloy / titanium alloy mesh material diffusion composite, specifically is completed according to the following steps:

[0032] I. The aluminum alloy plate is polished flat, the surface oil stain is removed, washed, and dried to obtain the pretreated aluminum alloy plate.

[0033] II. The titanium alloy mesh material is polished flat, the surface oil stain is removed, washed, and dried to obtain the pretreated titanium alloy mesh material.

[0034] III. A uniform copper film is deposited on the surface of the pretreated titanium alloy mesh material by electroplating process to obtain the titanium alloy mesh material containing copper film on the surface.

[0035] IV. A piece of titanium alloy mesh material containing copper film on the surface is placed between two pretreated aluminum alloy plates, then rivets are used for fixation, isolation agent is sprayed, and the package is placed in the package.

[0036] V. A gas pipe is placed at the package opening, and the package and the gas pipe are welded to seal the package and become the material to be rolled.

[0037] VI. The material to be rolled is vacuumed through the external gas pipe.

[0038] VII. The vacuumed material to be rolled is placed in a high-temperature furnace heated to the diffusion bonding temperature, and is kept for a period of time to obtain the material to be rolled.

[0039] VIII. The material to be rolled is taken out of the high-temperature furnace and quickly placed in a rolling mill for rolling, and then quickly placed in cold water for cooling after rolling is completed.

[0040] IX. After rolling is completed, stop the air supply and vacuuming.

[0041] X. The rolled material is cut by wire cutting to obtain the aluminum alloy / titanium alloy mesh material diffusion composite structure.

[0042] The embodiment solves the problem of long diffusion time required for high-strength bonding of the existing diffusion bonding method for preparing metal composite structures. The present application prepares a dense and uniform copper film on the surface of the mesh material by electroplating process, forms a copper plating film as an intermediate layer for diffusion bonding, and then realizes the diffusion bonding of dissimilar metals by plastic deformation of the plate and mesh material through rolling process, thereby avoiding the problem of extremely slow solid-state atomic diffusion in traditional diffusion bonding process, greatly improving the production efficiency of dissimilar metal diffusion bonding.

[0043] Specific implementation two: the difference between this embodiment and specific implementation one is that the aluminum alloy in step one is 5083 aluminum alloy; the cleaning in step one is ultrasonic cleaning with anhydrous ethanol; and the polishing stage in step one needs to ensure that the plate is smooth without obvious deformation. The other steps are the same as specific implementation one.

[0044] Specific implementation three: the difference between this embodiment and one of specific implementation one or two is that the titanium alloy in step two is TC4 titanium alloy; the cleaning in step two is ultrasonic cleaning with anhydrous ethanol; and the polishing stage in step two needs to ensure that the plate is smooth without obvious deformation. The other steps are the same as specific implementation one or two.

[0045] Specific implementation four: the difference between this embodiment and one of specific implementation one to three is that the titanium alloy mesh in step two has a mesh number of 60-120 meshes. The other steps are the same as specific implementation one to three.

[0046] Specific implementation five: the difference between this embodiment and one of specific implementation one to four is that the electrodeposition process in step three adopts a magnetic stirring deposition method; and the electrodeposition plating solution used in the electrodeposition process in step three is a CuSO4·5H2O solution with a concentration of 150 g / L. The other steps are the same as specific implementation one to four.

[0047] Specific implementation six: the difference between this embodiment and one of specific implementation one to five is that the parameters of the electrodeposition process in step three are: temperature 20-40℃, voltage 10-15V, and deposition time 1-5min. The other steps are the same as specific implementation one to five.

[0048] Specific implementation seven: the difference between this embodiment and one of specific implementation one to six is that before spraying the release agent in step four, adhesive tape is pasted around the fixed plate, and then the release agent is sprayed on the outer surface of the two aluminum alloy plates; the release agent is boron nitride. The other steps are the same as specific implementation one to six.

[0049] Specific implementation eight: the difference between this embodiment and one of specific implementation one to seven is that in step six, the material to be rolled is connected to a gas pipe to extract vacuum to a vacuum degree of 50Pa. The other steps are the same as specific implementation one to seven.

[0050] Specific implementation nine: the difference between this embodiment and one of specific implementation one to eight is that the diffusion connection temperature in step seven is 540-620℃; and the holding time in step seven is 20min~30min. The other steps are the same as specific implementation one to eight.

[0051] Specific implementation ten: the difference between this implementation and one of the specific implementations one to nine is that the rolling mill reduction in step eight is 30-50% of the thickness of the material to be rolled; the rolling speed of the rolling mill in step eight is 8r / min. The other steps are the same as those in specific implementations one to nine.

[0052] The beneficial effects of the present application are verified by the following examples:

[0053] Example 1: a diffusion bonding method for diffusion composite of aluminum alloy / titanium alloy mesh material, which is completed according to the following steps:

[0054] I. The aluminum alloy plate is polished to be flat, and the polishing stage ensures that the plate is smooth without obvious deformation, and removes surface oil stains, and is ultrasonically cleaned with anhydrous ethanol, and is blown dry to obtain a pretreated aluminum alloy plate;

[0055] The aluminum alloy in step one is fine-grained 5083 aluminum alloy, and the thickness is 2mm;

[0056] II. The titanium alloy mesh material is polished to be flat, and the polishing stage ensures that the plate is smooth without obvious deformation, and removes surface oil stains, and is ultrasonically cleaned with anhydrous ethanol, and is blown dry to obtain a pretreated titanium alloy mesh material;

[0057] The titanium alloy in step two is TC4 titanium alloy, and the thickness is 0.2mm;

[0058] The mesh number of the titanium alloy mesh material in step two is 90 mesh;

[0059] III. A uniform copper film is deposited on the surface of the pretreated titanium alloy mesh material by using an electrodeposition process to obtain a titanium alloy mesh material containing a copper film on the surface;

[0060] The electrodeposition process in step three is a magnetic stirring deposition method;

[0061] The electrodeposition plating solution used in the electrodeposition process in step three is a CuSO4·5H2O solution with a concentration of 150g / L;

[0062] The parameters of the electrodeposition process in step three are: temperature 25℃, voltage 10V, and deposition time 2min;

[0063] IV. A piece of titanium alloy mesh material containing a copper film on the surface is placed between two pretreated aluminum alloy plates, and then fixed with rivets, sprayed with a release agent, and placed in a package;

[0064] Before spraying the release agent in step four, the fixed plate is isolated by pasting adhesive tape around it, and then the release agent is sprayed on the outer surface of the two aluminum alloy plates; the release agent is boron nitride;

[0065] 5. Place a gas tube at the opening of the sleeve, weld the sleeve and the gas tube together to seal the inside of the sleeve, and the material to be rolled becomes the material.

[0066] 6. Vacuum the material to be rolled through an external air pipe;

[0067] In step six, the material to be rolled is evacuated to a vacuum level of 50 Pa through an external air pipe;

[0068] 7. Place the vacuumed material to be rolled into a high-temperature furnace that has been heated to the diffusion bonding temperature, and keep it at that temperature for a period of time to obtain the material to be rolled.

[0069] The diffusion connection temperature mentioned in step seven is 540℃;

[0070] The heat preservation time mentioned in step seven is 30 minutes;

[0071] 8. Remove the material to be rolled from the high-temperature furnace and quickly place it into the rolling mill for rolling. After rolling, quickly place it into cold water to cool.

[0072] The reduction of the rolling mill mentioned in step eight is 50% of the thickness of the material to be rolled;

[0073] The rolling speed of the rolling mill mentioned in step eight is 8 r / min;

[0074] 9. After rolling is completed, stop the ventilation and vacuuming.

[0075] 10. The rolled material is wire-cut to obtain an aluminum alloy / titanium alloy mesh diffusion composite structure, i.e., a formed part.

[0076] The sheet material formed in Example 1 has a three-layer composite structure, meaning that the sheet material is a composite structure consisting of two layers of sheet material and one layer of mesh material, such as... Figure 3 As shown, the total thickness of the three-layer structure is 1.9-2.1mm. Because the thickness varies at different points during the forming process, it is not a constant value. As can be seen from the figure, diffusion bonding is achieved through rolling, which results in short welding time, high process efficiency, uniform deformation of the sheet material, and a strong interfacial bonding strength of 96.3MPa.

[0077] Comparative Example 1:

[0078] 1. Grind the sheet material to be formed flat and remove surface oil. The sheet material is fine-grained 5083 aluminum alloy. During the grinding stage, ensure that the sheet is smooth and without obvious deformation. Clean it ultrasonically in anhydrous ethanol and then blow it dry for later use.

[0079] The thickness of the board material mentioned in step one is 2mm;

[0080] II. The two plates treated in step I are bonded together, and fixed by rivets. The periphery of the fixed plates is isolated by adhesive tape, and the isolation agent is boron nitride. Before spraying the isolation agent, the periphery of the plates should be isolated by adhesive tape. The area for spraying the isolation agent is only the surface of the plates, and the plates are put into the package;

[0081] III. A pipe is placed at the opening of the package, and the package and the pipe are welded to seal the package, thus forming a blank to be rolled;

[0082] IV. The blank to be rolled in step III is connected to the pipe to extract vacuum, thus obtaining a blank to be rolled after vacuum extraction;

[0083] V. The blank to be rolled after vacuum extraction is put into a high-temperature furnace heated to a diffusion connection temperature of 540℃, and kept for 30 min;

[0084] VI. The blank after keeping is taken out of the high-temperature furnace and quickly put into a rolling mill, and the rolling speed of the rolling mill is 8 r / min, and the rolling reduction is 50% of the total thickness of the plates and the mesh material. After rolling, the blank is quickly put into cold water for cooling;

[0085] VII. After rolling, the vacuum extraction is stopped;

[0086] VIII. The part is taken out by wire cutting, thus obtaining an aluminum alloy composite structure, i.e. a formed part.

[0087] The formed plate of Comparative Example 1 forms a double-layer composite structure, which means that the plate is a composite structure composed of two layers, and the total thickness of the double-layer structure is 1.8-2.0 mm. Because the thickness at each position changes during the forming process, it is not a fixed value.

[0088] The engineering stress-strain curve of the parts formed in Example 1 and Comparative Example 1 is shown in FIG. 1. Figure 4 As can be seen from FIG. 1, as the tensile strain continuously increases, the stress borne by the part continuously increases. The part prepared in Comparative Example 1 starts to break at 336 MPa, and the structure is basically completely destroyed when the strain is about 26%. The part prepared in Example 1 starts to break at 368 MPa, and then the structure is gradually destroyed, and the structure is basically completely destroyed when the strain is about 18%. The tensile strength of the part prepared in Example 1 is higher than that of the part prepared in Comparative Example 1, which indicates that the three-layer composite structure part prepared in Example 1 has higher resistance to destruction than the part without using the three-layer composite structure.

[0089] Although the present application has been disclosed with reference to the preferred embodiments above, it is not intended to limit the present application, and any person skilled in the art can make various modifications and modifications without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application should be defined by the claims.

Claims

1. A diffusion bonding method of diffusion bonding of an aluminum alloy / titanium alloy web material, characterized by The connecting method is specifically completed in the following steps: I. The aluminum alloy plate is polished flat, the surface oil stains are removed, cleaned, and dried to obtain the pretreated aluminum alloy plate; II. The titanium alloy mesh material is polished flat, the surface oil stains are removed, cleaned, and dried to obtain the pretreated titanium alloy mesh material; III. A uniform copper film is deposited on the surface of the pretreated titanium alloy mesh material by using an electrodeposition process to obtain the titanium alloy mesh material containing the copper film on the surface; IV. A piece of the titanium alloy mesh material containing the copper film on the surface is placed between two pieces of the pretreated aluminum alloy plate, then rivets are used for fixation, and an isolating agent is sprayed to be placed in a package; V. A gas pipe is taken and placed at the package opening, and the package and the gas pipe are welded to seal the package to become the material to be rolled; VI. The material to be rolled is vacuumized through an external gas pipe; VII. The vacuumized material to be rolled is placed in a high-temperature furnace heated to a diffusion connection temperature, and is kept for a period of time to obtain the material to be rolled; VIII. The material to be rolled is taken out from the high-temperature furnace and quickly placed in a rolling mill for rolling, and is quickly placed in cold water for cooling after the rolling is completed; IX. After the rolling is completed, the air supply and vacuumization are stopped; X. The rolled material is linearly cut to obtain the aluminum alloy / titanium alloy mesh diffusion composite structure.

2. The diffusion bonding method of diffusion bonding an aluminum alloy / titanium alloy web material according to claim 1, characterized by The aluminum alloy in step I is 5083 aluminum alloy; the cleaning in step I is ultrasonic cleaning using anhydrous ethanol; and the polishing stage in step I needs to ensure that the plate is smooth without obvious deformation.

3. The diffusion bonding method of claim 1, wherein the aluminum alloy / titanium alloy web diffusion composite is characterized by The titanium alloy in step II is TC4 titanium alloy; the cleaning in step II is ultrasonic cleaning using anhydrous ethanol; and the polishing stage in step II needs to ensure that the plate is smooth without obvious deformation.

4. The diffusion bonding method of claim 1, wherein The titanium alloy mesh material in step II has a mesh number of 60-120 meshes.

5. The diffusion bonding method of claim 1, wherein the aluminum alloy / titanium alloy web diffusion composite is characterized by The electrodeposition process in step III is a magnetic stirring deposition method; and the electrodeposition plating solution used in the electrodeposition process in step III is a CuSO4·5H2O solution with a concentration of 150 g / L.

6. The diffusion bonding method of an aluminum alloy / titanium alloy web diffusion composite according to claim 1, characterized by The parameters of the electrodeposition process in step III are as follows: temperature 20-40℃, voltage 10-15V, and deposition time 1-5 min.

7. The diffusion bonding method of an aluminum alloy / titanium alloy web diffusion composite according to claim 1, characterized by Before the isolating agent is sprayed in step IV, adhesive tape is pasted around the fixed plate, and then the isolating agent is sprayed on the outer surfaces of the two aluminum alloy plates; the isolating agent is boron nitride.

8. The diffusion bonding method of claim 1, wherein the aluminum alloy / titanium alloy web diffusion composite is characterized by In step VI, the material to be rolled is vacuumized through an external gas pipe to a vacuum degree of 50 Pa.

9. The diffusion bonding method of claim 1, wherein the aluminum alloy / titanium alloy web material diffusion composite is characterized by The diffusion connection temperature in step VII is 540-620℃; and the keeping time in step VII is 20 min-30 min.

10. The diffusion bonding method of an aluminum alloy / titanium alloy web material diffusion composite according to claim 1, characterized by The rolling mill in step VIII has a reduction of 30-50% of the thickness of the material to be rolled; and the rolling speed of the rolling mill in step VIII is 8 r / min.

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