A soldering and metal sealing method

Abstract

The application relates to the technical field of sealing technology, in particular to a solder and a sealing method of metal, the solder is composed of alloy powder, ferrocene-based ionic liquid, epoxy acrylate resin, a curing agent and a diluent; the solder and the sealing method can realize high-quality sealing of a titanium / steel heterogeneous structure, the sealing joint strength is greater than or equal to 200 MPa, and the solder and the sealing method have great significance for high-quality and high-efficiency connection of heterogeneous materials.

Description

Technical Field

[0001] This invention relates to the field of sealing technology, specifically to a sealing method for solder and metal. Background Technology

[0002] Heterogeneous metal composite structures can "combine the strengths and compensate for the weaknesses of different materials," fully leveraging the performance advantages and economic benefits of various metals, and their importance in modern manufacturing is increasingly prominent. Titanium and titanium alloys possess many excellent properties, such as high specific strength, excellent corrosion resistance, and good plasticity, while steel has the characteristics of high strength, excellent plasticity and toughness, good heat resistance, and low price. The engineering application demand for titanium / steel heterogeneous composite structures is very urgent, and they are widely used in chemical equipment, aerospace, automotive, shipbuilding, and construction engineering. Welding is one of the important methods for manufacturing titanium / steel heterogeneous structures. However, due to the significant differences in the physical, chemical, and metallurgical properties between titanium and steel, high-quality sealing of titanium / steel heterogeneous structures has always been a challenge and pain point in the industry. Summary of the Invention

[0003] Purpose of the invention: In view of the above-mentioned technical problems, the present invention proposes a method for sealing solder and metal.

[0004] The technical solution adopted is as follows: A solder is composed of alloy powder, ferrocene-based ionic liquid, epoxy acrylate resin, curing agent, and diluent.

[0005] Furthermore, the alloy powder is an Ag-Cu-Ti-Co quaternary alloy powder.

[0006] Furthermore, the proportions of each element in the Ag-Cu-Ti-Co quaternary alloy powder are Ag 50wt%, Cu: 30wt%, Ti: 10wt%, and Co: 10wt%.

[0007] Furthermore, the preparation method of Ag-Cu-Ti-Co quaternary alloy powder is as follows: Ag powder, Cu powder, Ti powder, and Co powder are mixed evenly and added to a dehumidified crucible. The melting furnace is evacuated and heated for melting. The vacuum level inside the melting furnace is reduced to less than 10 Pa. When the raw materials begin to melt, argon gas is introduced, and the heating continues until the raw materials are completely melted into an alloy liquid. The high-pressure argon gas valve of the nozzle is opened, and the resulting alloy liquid is poured into the preheating intermediate tundish of the vacuum induction melting gas atomization powder making equipment. It flows out along the guide pipe at the bottom of the intermediate tundish into the atomization chamber, where it is atomized and cooled by high-speed argon gas to obtain alloy powder. After atomization powder making is completed, it is collected and sieved.

[0008] Furthermore, the mass ratio of the alloy powder, ferrocene-based ionic liquid, epoxy acrylate resin, curing agent, and diluent is 50-60:1-5:5-10:1-3:10-20.

[0009] Furthermore, the structural formula of the ferrocene-based ionic liquid is shown below: Where n≤10, and X is a halogen element. Furthermore, n is 6, and X is Br.

[0010] Furthermore, the preparation method of the ferrocene-based ionic liquid is as follows: Ferrocene carboxylic acid and haloalcohol are esterified to obtain an intermediate, which is then reacted with 1-vinylimidazole to obtain the final product.

[0011] Furthermore, the preparation method of the ferrocene-based ionic liquid is as follows: Ferrocene carboxylic acid and 4-dimethylaminopyridine were first dissolved in an organic solvent to obtain solution A. Then, bromosubstituted alkyl alcohol and N,N-dicyclohexylcarboimide were dissolved in the organic solvent to obtain solutions B and C, respectively. Solutions B and C were then slowly added dropwise to solution A in sequence. After the reaction was complete, the mixture was filtered, and the filtrate was purified to obtain an intermediate. The intermediate, 1-vinylimidazolium, and 2,6-di-tert-butyl-p-cresol (BHT) were added to acetone and refluxed under a nitrogen atmosphere. The reaction solution was then added to diethyl ether to precipitate, and the product was collected and dried under vacuum.

[0012] Furthermore, the curing agent is composed of benzoyl peroxide and N,N-dimethylaniline.

[0013] Furthermore, the mass ratio of benzoyl peroxide to N,N-dimethylaniline is 1-4:1-4.

[0014] Furthermore, the diluent is composed of methyl methacrylate and xylene.

[0015] Furthermore, the mass ratio of methyl methacrylate to xylene is 1-4:1-4.

[0016] This invention also provides a method for sealing metals: A porous copper transition film is prepared on the surface of the metal, then solder is coated on the surface of the porous transition film, and finally vacuum heating is used for sealing.

[0017] Furthermore, the porous copper transition film layer is prepared by electroplating.

[0018] Furthermore, the method for preparing the porous copper transition film is as follows: Prepare an electroplating solution containing copper acetate and chitosan. Use the metal to be plated as the cathode and pure copper as the anode. After electroplating at a constant voltage, remove the cathode, wash, and vacuum dry.

[0019] Furthermore, the sealing temperature is 850-950℃.

[0020] The beneficial effects of this invention are: This invention provides a solder in which cobalt in the solder alloy powder, as a transition metal, can improve the high-temperature strength and oxidation resistance of the solder, improve the wetting and spreading properties of the interface, and may also form a more tough transition phase, adjust the microstructure of the brazed joint, suppress the formation of extremely brittle phases, and reduce the influence of brittle compounds on the joint strength. Electroplated porous copper transition film can promote solder wetting and spreading, and act as a "diffusion bridge" to promote element interdiffusion and intermetallic compound formation between the solder and the base metal, thereby enhancing joint strength. Its porous structure provides an "anchoring effect" for the solder; after melting, the solder penetrates into the pores and cools to form a mechanical bond, enhancing joint strength. The pores also act as capillary action, guiding the solder to distribute and wet more evenly, which is particularly beneficial for complex geometries or multi-layer brazing. Furthermore, it can absorb some of the thermal stress during the brazing cooling process, reducing crack initiation.

[0021] Ferrocene-based ionic liquids can participate in the curing of epoxy acrylate resins, enabling the alloy powder to be evenly dispersed and spread more easily in the solder, improving the wettability of the metal surface. In addition, during heat sealing, it decomposes, and the iron atoms in the decomposition products aggregate into nano-sized particles. These iron nanoparticles adsorb and dissolve the carbon atoms decomposed from the carbon source, and after reaching supersaturation, they self-assemble to form carbon nanotubes. These carbon nanotubes can form a mechanical interlocking structure with the porous copper transition film layer together with the molten solder, further enhancing the joint strength. Furthermore, the iron element can also be dissolved into the joint to improve the joint strength.

[0022] The solder and sealing method provided by this invention can achieve high-quality sealing of titanium / steel heterostructures, with a joint strength ≥200MPa, which is of great significance for high-quality and efficient sealing of heterostructures. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the sandwich structure in Embodiment 1 of the present invention; The labels in the diagram represent: 1-Pure titanium, 2-Porous copper transition film, 3-Solder, 4-Porous copper transition film, 5-304 stainless steel. Detailed Implementation

[0024] Unless otherwise specified in the examples, the conditions were performed under standard conditions or as recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products. Techniques not mentioned in this invention refer to existing technologies. Unless otherwise specified, the following examples and comparative examples are parallel experiments, using the same processing steps and parameters.

[0025] Example 1: A solder is composed of Ag-Cu-Ti-Co quaternary alloy powder, ferrocene-based ionic liquid, epoxy acrylate resin, benzoyl peroxide, N,N-dimethylaniline, methyl methacrylate and xylene in a mass ratio of 55:3:8:1:1:5:12.

[0026] The preparation method of Ag-Cu-Ti-Co quaternary alloy powder is as follows: The crucible was fixed in the melting furnace and heated to remove moisture. Then, 50wt% high-purity Ag powder, 30wt% high-purity Cu powder, 10wt% high-purity Ti powder, and 10wt% high-purity Co powder were mixed evenly and added to the dehumidified crucible. The melting furnace was evacuated and heated for melting. The evacuation was continued until the vacuum level inside the furnace was less than 10 Pa. The temperature was raised until the raw materials began to melt. Argon gas was then introduced to achieve an argon pressure of 0.05 MPa. Heating continued until the raw materials were completely melted. The alloy liquid is fully melted, and the high-pressure argon valve of the nozzle is opened. After the gas pressure stabilizes at about 3.5 MPa, the obtained alloy liquid is poured into the tundish of the vacuum induction melting gas atomization powder making equipment (the tundish is preheated to 1000℃). It flows out along the guide pipe at the bottom of the tundish into the atomization chamber, where it is atomized and cooled by high-speed argon gas to obtain alloy powder. After the atomization powder making is completed, the alloy powder is collected and sieved using a mesh screen to obtain Ag-Cu-Ti-Co quaternary alloy powder with a particle size of 400 mesh.

[0027] The preparation method of ferrocene-based ionic liquids is as follows: Ferrocene carboxylic acid (4.6098 g, 20 mmol) and 4-dimethylaminopyridine (DMAP, 2.4443 g, 20 mmol) were first dissolved in 100 mL of anhydrous dichloromethane to obtain solution A. Then, 6-bromohexanol (3.6214 g, 20 mmol) and N,N-dicyclohexylcarboimide (DCC, 6.1906 g, 30 mmol) were each dissolved in 50 mL of anhydrous dichloromethane to obtain solutions B and C, respectively. Solutions B and C were then slowly added dropwise to solution A in sequence, and the reaction was carried out at room temperature for 24 h. After the reaction was completed, the mixture was filtered, and the filtrate was purified by column chromatography using petroleum ether:ethyl acetate = 4:1 (v / v) as the eluent to obtain the intermediate with a purity (HPLC) of 99.3% and a yield of 61.7%.

[0028] The intermediate (3.9310 g, 10 mmol), 1-vinylimidazole (0.9411 g, 10 mmol), and 2,6-di-tert-butyl-p-cresol (BHT, 0.2436 g, 0.11 mmol) were added to a round-bottom flask containing 50 mL of acetone. The mixture was stirred and heated to reflux for 72 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was added dropwise to 500 mL of cold diethyl ether to precipitate. The precipitated product was collected and dried under vacuum. The purity (HPLC) was 99.1%, and the yield was 43.9%.

[0029] A method for sealing metal: Epoxy acrylate resin, ferrocene-based ionic liquid, methyl methacrylate and xylene are mixed evenly, then Ag-Cu-Ti-Co quaternary alloy powder is added, ground in a mortar, and then benzoyl peroxide and N,N-dimethylaniline are added and stirred to obtain solder.

[0030] Copper acetate was added to deionized water to prepare a 0.2 mol / L solution. 2 g of chitosan was weighed and dissolved in 100 ml of 2% acetic acid solution. The solution was stirred to dissolve the chitosan solution. Then, 45 ml of copper acetate solution and 90 ml of chitosan solution were mixed and stirred evenly to obtain an electroplating solution. Pure titanium and 304 stainless steel were used as cathodes (one side of the surface was covered with a plastic film), and pure copper was used as the anode. Electroplating was performed at 5V for 5 min. The cathodes were removed, the plastic film was peeled off, and the solution was washed with 10% acetic acid solution and deionized water and then vacuum dried to obtain a porous copper transition film layer.

[0031] Solder is evenly applied to a porous copper transition film layer of 304 stainless steel, and then a porous copper transition film layer of pure titanium is placed on top to form a sandwich structure. (See [link]). Figure 1 The samples were then placed in a vacuum brazing furnace and heated to 900°C at a rate of 10°C / min. After holding at that temperature for 15 minutes, the samples were cooled to room temperature with the furnace. The mechanical properties of the joint were tested using shear strength as a reference. The tests were conducted using a universal testing machine at a rate of 0.5 mm / min. A total of 5 samples were tested, and the average value of the test results was taken. The shear strength of the joint was 282.6 MPa.

[0032] Example 2: A solder is composed of Ag-Cu-Ti-Co quaternary alloy powder, ferrocene-based ionic liquid, epoxy acrylate resin, benzoyl peroxide, N,N-dimethylaniline, methyl methacrylate and xylene in a mass ratio of 60:5:10:1:1:5:15.

[0033] The preparation methods for Ag-Cu-Ti-Co quaternary alloy powder and ferrocene-based ionic liquid are the same as in Example 1.

[0034] A method for sealing metal: Epoxy acrylate resin, ferrocene-based ionic liquid, methyl methacrylate and xylene are mixed evenly, then Ag-Cu-Ti-Co quaternary alloy powder is added, ground in a mortar, and then benzoyl peroxide and N,N-dimethylaniline are added and stirred to obtain solder.

[0035] Copper acetate was added to deionized water to prepare a 0.2 mol / L solution. 2 g of chitosan was weighed and dissolved in 100 ml of 2% acetic acid solution. The solution was stirred to dissolve the chitosan solution. Then, 45 ml of copper acetate solution and 90 ml of chitosan solution were mixed and stirred evenly to obtain an electroplating solution. Pure titanium and 304 stainless steel were used as cathodes (one side of the surface was covered with a plastic film), and pure copper was used as the anode. Electroplating was performed at 5V for 5 min. The cathodes were removed, the plastic film was peeled off, and the solution was washed with 10% acetic acid solution and deionized water and then vacuum dried to obtain a porous copper transition film layer.

[0036] Solder was evenly applied to a porous copper transition film layer of 304 stainless steel, and then a porous copper transition film layer of pure titanium was placed on top to form a sandwich structure. The structure was then placed in a vacuum brazing furnace and heated to 850°C at a rate of 10°C / min. After holding at that temperature for 15 minutes, the structure was cooled to room temperature with the furnace. The mechanical properties of the joint were tested using shear strength as a reference. The tests were conducted using a universal testing machine at a rate of 0.5 mm / min, and a total of 5 samples were tested. The average value of the test results was taken. The shear strength of the joint was 256.4 MPa.

[0037] Example 3: A solder is composed of Ag-Cu-Ti-Co quaternary alloy powder, ferrocene-based ionic liquid, epoxy acrylate resin, benzoyl peroxide, N,N-dimethylaniline, methyl methacrylate and xylene in a mass ratio of 50:1:5:1:1:5:10.

[0038] The preparation methods for Ag-Cu-Ti-Co quaternary alloy powder and ferrocene-based ionic liquid are the same as in Example 1.

[0039] A method for sealing metal: Epoxy acrylate resin, ferrocene-based ionic liquid, methyl methacrylate and xylene are mixed evenly, then Ag-Cu-Ti-Co quaternary alloy powder is added, ground in a mortar, and then benzoyl peroxide and N,N-dimethylaniline are added and stirred to obtain solder.

[0040] Copper acetate was added to deionized water to prepare a 0.2 mol / L solution. 2 g of chitosan was weighed and dissolved in 100 ml of 2% acetic acid solution. The solution was stirred to dissolve the chitosan solution. Then, 45 ml of copper acetate solution and 90 ml of chitosan solution were mixed and stirred evenly to obtain an electroplating solution. Pure titanium and 304 stainless steel were used as cathodes (one side of the surface was covered with a plastic film), and pure copper was used as the anode. Electroplating was performed at 5V for 5 min. The cathodes were removed, the plastic film was peeled off, and the solution was washed with 10% acetic acid solution and deionized water and then vacuum dried to obtain a porous copper transition film layer.

[0041] Solder was evenly applied to a porous copper transition film layer of 304 stainless steel, and then a porous copper transition film layer of pure titanium was placed on top to form a sandwich structure. The structure was then placed in a vacuum brazing furnace and heated to 950°C at a rate of 10°C / min. After holding at that temperature for 15 minutes, the structure was cooled to room temperature with the furnace. The mechanical properties of the joint were tested using shear strength as a reference. The tests were conducted using a universal testing machine at a rate of 0.5 mm / min, and a total of 5 samples were tested. The average value of the test results was taken. The shear strength of the joint was 270.2 MPa.

[0042] Example 4: Similar to Example 1, except that the solder in this example consists of Ag-Cu-Ti-Co quaternary alloy powder, ferrocene-based ionic liquid, epoxy acrylate resin, benzoyl peroxide, N,N-dimethylaniline, methyl methacrylate, and xylene in a mass ratio of 60:1:10:10:1:1:5:10. The mechanical properties of the joint in this example are measured using shear strength as a reference. A universal testing machine was used to test five samples at a rate of 0.5 mm / min, and the average value of the test results was taken. The shear strength of the joint was 246.6 MPa.

[0043] Example 5: Similar to Example 1, except that the solder in this example consists of Ag-Cu-Ti-Co quaternary alloy powder, ferrocene-based ionic liquid, epoxy acrylate resin, benzoyl peroxide, N,N-dimethylaniline, methyl methacrylate, and xylene in a mass ratio of 50:5:5:1:1:5:15. The mechanical properties of the joint in this example are measured using shear strength as a reference. A universal testing machine was used to test five samples at a rate of 0.5 mm / min, and the average value was taken. The shear strength of the joint was 263.7 MPa.

[0044] Comparative Example 1: The results are essentially the same as in Example 1, except that no ferrocene-based ionic liquid is added. The mechanical properties of this comparative joint are measured using shear strength as a reference. A universal testing machine was used to test five specimens at a rate of 0.5 mm / min, and the average value of the test results was taken. The shear strength of the joint was 157.3 MPa.

[0045] Comparative Example 2: The results are essentially the same as in Example 1, except that ferrocene is used instead of the ferrocene-based ionic liquid. The mechanical properties of this comparative joint are measured using shear strength as a reference. A universal testing machine was used to test five specimens at a rate of 0.5 mm / min, and the average value of the test results was taken. The shear strength of the joint was 190.4 MPa.

[0046] Comparative Example 3: The example is basically the same as Example 1, except that Ag-Cu-Ti ternary alloy powder is used instead of Ag-Cu-Ti-Co quaternary alloy powder.

[0047] The preparation method of Ag-Cu-Ti ternary alloy powder is similar to that in Example 1, except that high-purity Co powder is not added. The mechanical properties of the comparative joint were tested using shear strength as a reference. A universal testing machine was used at a rate of 0.5 mm / min, and a total of 5 samples were tested. The average value of the test results was taken. The shear strength of the joint was 230.3 MPa.

[0048] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. 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 of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A solder, characterized in that, It is composed of alloy powder, ferrocene-based ionic liquid, epoxy acrylate resin, curing agent, and diluent; The alloy powder is Ag-Cu-Ti-Co quaternary alloy powder; The mass ratio of the alloy powder, ferrocene-based ionic liquid, epoxy acrylate resin, curing agent, and diluent is 50-60:1-5:5-10:1-3:10-20. The structural formula of the ferrocene-based ionic liquid is shown below: ； Where n≤10, and X is a halogen element; The preparation method of the ferrocene-based ionic liquid is as follows: Ferrocene carboxylic acid and haloalcohol are esterified to give an intermediate, which is then reacted with 1-vinylimidazole to obtain the final product. The curing agent is composed of benzoyl peroxide and N,N-dimethylaniline; The diluent consists of methyl methacrylate and xylene.

2. A method for sealing metal, characterized in that, First, a porous copper transition film is prepared on the surface of the metal. Then, the solder described in claim 1 is coated on the surface of the porous transition film. Finally, it is sealed by vacuum heating.

3. The metal sealing method as described in claim 2, characterized in that, The porous copper transition film layer is prepared by electroplating.

4. The metal sealing method as described in claim 2, characterized in that, The sealing temperature is 850-950℃.

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