A preparation method of AgCuTi active solder

Abstract

The present invention provides a method for preparing an AgCuTi active solder, relating to the technical field of brazing materials. The preparation method comprises the following steps: pretreating a titanium foil, sequentially electroplating the surface with silver and copper, and diffusing the electroplated titanium foil in a vacuum environment at 600-700°C for 24 hours to obtain the AgCuTi solder. The method provided by the present invention can easily and conveniently prepare sheet- and strip-shaped AgCuTi active solders, and the active solders are less susceptible to the presence of CuTi intermetallic compounds while exhibiting good performance.

Description

Technical Field

[0001] The invention relates to the technical field of brazing materials, and in particular to a preparation method of AgCuTi active brazing filler metal. Background Art

[0002] AgCuTi solder contains the active element Ti, which reacts with C, N, Si, and most ceramics and metals. Therefore, AgCuTi solder is widely used in the field of vacuum brazing of ceramics and ceramics, ceramics and metals, and metals and carbon materials. However, the molding of traditional AgCuTi solder is relatively difficult, which limits the further promotion and application of AgCuTi solder. The main reason for the difficulty in molding AgCuTi solder is that the Cu and Ti in AgCuTi easily react to form brittle intermetallic compounds such as TiCu, Ti3Cu4, Ti2Cu3 and TiCu4. These intermetallic compounds are highly brittle and have poor plasticity, which is very unfavorable for the processing and molding of AgCuTi solder.

[0003] Currently, the main methods for preparing AgCuTi solders include melting and rolling, mechanical alloying, and high-energy ball milling-hot pressing. However, the melting and rolling method is prone to segregation, resulting in uneven chemical composition and the aggregation of CuTi compounds. In addition, Ti easily reacts with the crucible, affecting the composition of the solder. AgCuTi solders prepared by mechanical alloying and high-energy ball milling-hot pressing have the advantages of small particles and uniform dispersion. However, the high equipment cost, long production cycle, difficult operation, and limited output limit their application range. In addition, the AgCuTi solders prepared by mechanical alloying and high-energy ball milling-hot pressing are usually in powder form, which is not suitable for the preparation of large brazing parts and complex shapes or precision weldments.

[0004] Therefore, it is urgent to propose a method for preparing a brazing material that can be used to prepare sheet and strip brazing materials and improve the problem that CuTi compounds are easily present in AgCuTi brazing materials. Summary of the Invention

[0005] The object of the present invention is to provide a method for preparing an AgCuTi active solder, which can simply and conveniently prepare sheet-shaped and strip-shaped AgCuTi active solders, wherein CuTi compounds are unlikely to appear in the active solder and the active solder has good performance.

[0006] The invention provides a preparation method of an AgCuTi active solder, comprising the following steps: pre-treating a titanium foil, sequentially electroplating silver and copper on the surface, and diffusing the electroplated titanium foil in a vacuum environment at 600-700°C for 24 hours to obtain the AgCuTi solder.

[0007] The beneficial effect of the preparation method of the AgCuTi active solder provided by the present invention is that it can simply and conveniently prepare a sheet or strip-shaped AgCuTi active solder with good performance, isolate the contact between titanium and copper through the silver plating layer, and effectively control the formation of CuTi intermetallic compounds.

[0008] Optionally, when the electroplated titanium foil is diffused in a vacuum environment at 600-700°C for 24 hours, the vacuum degree of the vacuum environment is controlled to be 2×10 -3 Pa-5×10 -4 Pa.

[0009] Optionally, the process of sequentially electroplating silver and copper on the surface includes the following steps: placing the pretreated titanium foil in a silver electroplating solution, plating for 2h-3h in an environment of 25±2°C, taking it out, cleaning and drying it to obtain a silver-plated titanium foil; placing the silver-plated titanium foil in a copper electroplating solution, plating for 50min-90min in an environment of 25°C, cleaning and drying it to obtain a silver / copper double-plated titanium foil.

[0010] Optionally, the electroplating silver solution is prepared by the following steps: dissolving 200g of sodium thiosulfate in deionized water to obtain a sodium thiosulfate solution; dissolving 40g of silver nitrate and 40g of potassium metabisulfite in deionized water respectively, and pouring the potassium metabisulfite solution into the silver nitrate solution under stirring to obtain a silver metabisulfite mixed solution; immediately mixing the sodium thiosulfate solution and the silver metabisulfite mixed solution under stirring to generate a slightly yellow clear solution, adding water to dilute to 1000mL, and then filtering to obtain the electroplating silver solution.

[0011] Optionally, the copper electroplating solution is prepared by the following steps: dissolving 250g of copper sulfate and 40g of glucose in deionized water respectively, and after the copper sulfate solution is cooled, slowly adding 38mL of concentrated sulfuric acid to the copper sulfate solution and stirring, then adding the glucose solution and stirring to mix evenly, and fixing the volume to 1000mL to obtain a copper plating solution.

[0012] Optionally, the pretreated titanium foil is placed in a silver electroplating solution and plated for 2-3 hours at a temperature of 25±2°C while controlling the electroplating current density to be 0.2A / dm 2 -0.5A / dm 2 .

[0013] Optionally, the silver-plated titanium foil is placed in a copper electroplating solution and plated for 50-90 minutes at 25±2°C, with the electroplating current density controlled to be 1.2A / dm 2 -1.5A / dm 2 .

[0014] Optionally, the process of pre-treating the titanium foil includes sequentially performing degreasing, alkali washing, pickling and activation.

[0015] Optionally, when performing the degreasing, the surface of the titanium foil is wiped with acetone, and the wiped surface of the titanium foil is cleaned with deionized water to obtain the degreased titanium foil; when performing the alkali washing, the degreased titanium foil is placed in a mixed alkali solution in a constant temperature water bath at 70°C and washed for 15min-20min, taken out, washed with deionized water and dried to obtain the alkali-washed titanium foil; when performing the acid washing, the alkali-washed titanium foil is placed in an acid washing solution at 25°C and immersed for 2min, taken out, washed with deionized water and dried to obtain the acid-washed titanium foil; when performing the activation, the acid-washed titanium foil is placed in an activation solution at 25°C and immersed for 5min, taken out, washed with deionized water and dried to obtain the activated titanium foil.

[0016] Optionally, the mixed alkaline solution is prepared by mixing 35g / L sodium hydroxide solution, 35g / L sodium carbonate solution and 35g / L sodium phosphate solution; the pickling solution is prepared by mixing 400mL / L hydrochloric acid and 65mL / L hydrofluoric acid; and the activation solution is prepared by mixing 120mL / L hydrofluoric acid and 850mL / L hydrochloric acid. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of a method for preparing an AgCuTi active solder in the present invention;

[0018] Figure 2 The figure is a specific flow chart of step S2 in the method for preparing an AgCuTi active solder in the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the invention belongs. The words "including" and similar words used in this article mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0020] The present invention provides a method for preparing an AgCuTi active brazing filler metal. The method comprises the following steps: pre-treating a titanium foil, sequentially electroplating the surface with silver and copper, and diffusing the plated titanium foil in a vacuum environment at 600-700°C for 24 hours to obtain the AgCuTi brazing filler metal. This AgCuTi brazing filler metal exhibits excellent wettability and can be used for brazing systems such as ceramic-ceramic, ceramic-metal, and metal-composite materials.

[0021] In some embodiments, the grade of the titanium foil is TA2.

[0022] In some embodiments, the original thickness of the titanium foil is 20 μm, the thickness of the silver layer electroplated on the surface of the titanium foil is about 135 μm, and the thickness of the copper layer electroplated on the surface of the silver layer is about 60 μm.

[0023] In some embodiments, the total thickness of the AgCuTi solder is controlled between 180 μm and 220 μm.

[0024] In some embodiments, the electroplated titanium foil is diffused in a vacuum environment to form a diffusion layer of about 50 μm.

[0025] In some embodiments, see Figure 1 A method for preparing an AgCuTi active solder comprises the following steps:

[0026] S1. Pretreatment: Surface pretreatment of titanium foil;

[0027] S2. Surface electroplating: silver and copper are sequentially electroplated on the surface of the pretreated titanium foil;

[0028] S3. Vacuum diffusion: Place the electroplated titanium foil in a 600-700μ vacuum environment and diffuse it for 24±2h to obtain AgCuTi solder.

[0029] In some embodiments, step S1 of performing surface pretreatment on the titanium foil includes sequentially performing degreasing, alkali washing, acid washing, and activation.

[0030] In some further embodiments, degreasing the titanium foil surface includes: cleaning the titanium foil surface with deionized water, wiping the titanium foil surface with acetone, and then cleaning the titanium foil surface with deionized water to obtain a degreased titanium foil.

[0031] In some further embodiments, the surface alkali washing of the degreased titanium foil includes: placing the degreased titanium foil in a mixed alkali solution in a constant temperature water bath at 70° C. for 15-20 minutes, taking it out, washing it with deionized water, and drying it to obtain the alkali-washed titanium foil.

[0032] In some further embodiments, the mixed alkaline solution used is prepared by mixing 35 g / L sodium hydroxide solution, 35 g / L sodium carbonate solution and 35 g / L sodium phosphate solution.

[0033] In some further embodiments, the surface pickling of the alkali-washed titanium foil includes: immersing the alkali-washed titanium foil in a 25° C. pickling solution for 2 minutes, taking it out, washing it with deionized water, and drying it to obtain the pickled titanium foil.

[0034] In some further embodiments, the pickling solution used is a mixture of 400 mL / L hydrochloric acid and 65 mL / L hydrofluoric acid.

[0035] In some further embodiments, the surface activation of the pickled titanium foil includes: immersing the pickled titanium foil in an activation solution at 25° C. for 5 minutes, taking it out, washing it with deionized water, and drying it to obtain the activated titanium foil.

[0036] In some further embodiments, the activation solution used is a mixture of 120 mL / L hydrofluoric acid and 850 mL / L hydrochloric acid.

[0037] In some embodiments, see Figure 2 , executing step S2 includes the following steps:

[0038] S21, silver electroplating: placing the pretreated titanium foil in a silver electroplating solution, plating for 2-3 hours in an environment of 25±2°C, taking it out, cleaning and drying it to obtain a silver-plated titanium foil;

[0039] S22. Copper layer electroplating: Place the silver-plated titanium foil in a copper electroplating solution, plate for 50-90 minutes in an environment of 25±2°C, then wash and dry to obtain a silver / copper double-plated titanium foil.

[0040] In some embodiments, when performing S21 to electroplating the silver layer, a silver electroplating solution and a copper electroplating solution to be used are prepared in advance.

[0041] In some further embodiments, the silver electroplating solution is prepared by the following steps:

[0042] Dissolve 200 g of sodium thiosulfate in deionized water to obtain a sodium thiosulfate solution;

[0043] Dissolve 40 g of silver nitrate and 40 g of potassium metabisulfite in deionized water respectively, and pour the potassium metabisulfite solution into the silver nitrate solution while stirring to obtain a silver metabisulfite mixed solution;

[0044] Immediately mix the sodium thiosulfate solution and the silver metabisulfite mixed solution under stirring to generate a slightly yellow clear solution, add water to make the volume to 1000 mL, and then filter to obtain the electroplating silver solution.

[0045] In some further embodiments, after the volume is fixed, the solution is allowed to stand for 3 hours, and then a small amount of activated carbon is added to filter the silver plating solution to obtain an electroplating silver solution.

[0046] In some further embodiments, the copper electroplating solution is prepared by the following steps:

[0047] Dissolve 250g of copper sulfate and 40g of glucose in deionized water respectively. After the copper sulfate solution cools, slowly add 38mL of concentrated sulfuric acid to the copper sulfate solution and stir. Then add the glucose solution, mix well, and dilute to 1000mL to obtain a copper electroplating solution.

[0048] In some further embodiments, when executing step S21, the current density during electroplating is controlled to be 0.2A / dm 2 -0.5A / dm 2 .

[0049] In some further embodiments, when executing step S22, the current density during electroplating is controlled to be 1.2A / dm 2 -1.5A / dm 2 .

[0050] In some embodiments, when executing step S3, the vacuum degree of the vacuum environment is controlled to be 2×10 -3 Pa-5×10 -4 Pa.

[0051] Example 1

[0052] See also Figure 1 and Figure 2 This embodiment 1 discloses a method for preparing an AgCuTi active solder, comprising the following steps:

[0053] S1. Pretreatment: Degrease, alkali wash, pickle and activate a 20 μm thick TA2 titanium foil in sequence to obtain a pretreated titanium foil; wherein, when degreasing the titanium foil, clean the surface of the titanium foil with deionized water, wipe the surface of the titanium foil with acetone, and then clean the surface of the titanium foil with deionized water to obtain the degreased titanium foil, place it in a mixed alkali solution in a constant temperature water bath at 70°C for 15-20 minutes, take it out, rinse it with deionized water and dry it, and then immerse the alkali-washed titanium foil in a 25°C pickling solution for 2 minutes. n, take out, wash with deionized water and dry to obtain the pickled titanium foil, place it in the activation solution at 25°C and immerse it for 5 minutes, take it out, wash with deionized water and dry it to obtain the activated titanium foil; specifically, the mixed alkaline solution used is a mixture of 35g / L sodium hydroxide solution, 35g / L sodium carbonate solution and 35g / L sodium phosphate solution, the pickling solution used is a mixture of 400mL / L hydrochloric acid and 65mL / L hydrofluoric acid, and the activation solution used is a mixture of 120mL / L hydrofluoric acid and 850mL / L hydrochloric acid;

[0054] S2. Surface plating:

[0055] S21, silver layer electroplating: place the pretreated titanium foil in the silver electroplating solution, and plate it at room temperature of 25℃ for 150min, with the current density controlled at 0.4A / dm 2 After the electroplating is completed, the silver-plated titanium foil is removed, cleaned, and dried to obtain a silver-plated titanium foil; wherein the silver plating solution is prepared by the following steps: dissolving 200g of sodium thiosulfate in deionized water to obtain a sodium thiosulfate solution; dissolving 40g of silver nitrate and 40g of potassium metabisulfite in deionized water respectively, and pouring the potassium metabisulfite solution into the silver nitrate solution under stirring to obtain a silver metabisulfite mixed solution; immediately mixing the sodium thiosulfate solution and the silver metabisulfite mixed solution under stirring to generate a slightly yellow clear solution, adding water to dilute to 1000mL, and then filtering to obtain an electroplated silver solution;

[0056] S22, copper layer electroplating: placing a silver-plated titanium foil in a copper electroplating solution, plating for 60 minutes at room temperature of 25°C, controlling the current density to 1.2A / dm2, taking out and cleaning after completion of electroplating, and drying in a vacuum drying oven at 50°C to obtain a silver / copper double-plated titanium foil; wherein the copper plating solution is prepared by the following steps: dissolving 250g of copper sulfate and 40g of glucose in deionized water respectively, and after the copper sulfate solution is cooled, slowly adding 38mL of concentrated sulfuric acid to the copper sulfate solution with stirring, then adding the glucose solution, mixing evenly, and fixing the volume to 1000mL to obtain the copper electroplating solution;

[0057] S3, Vacuum Diffusion: Place the silver / copper double-coated titanium foil in a vacuum environment at 650℃ and control the vacuum degree to 3×10 -4 pa-4×10 -4Pa, allowed to diffuse for 24 hours and then cooled to room temperature to obtain flaky AgCu-4.5Ti solder.

[0058] Example 2

[0059] The difference between Example 2 and Example 1 is that in step S21, the plating time of the silver layer is controlled to be 130 minutes, and in step S22, the plating time of the copper layer is controlled to be 55 minutes; thus, a sheet-like AgCu-5Ti solder is obtained after step S3.

[0060] Example 3

[0061] The difference between Example 3 and Example 1 is that in step S21, the plating time of the silver layer is controlled to be 180 minutes, and in step S22, the plating time of the copper layer is controlled to be 70 minutes; thus, after step S3, a sheet-like AgCu-4Ti solder is obtained.

[0062] While the embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations of these embodiments are possible. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as set forth in the claims. Furthermore, the invention described herein is susceptible to other embodiments and may be practiced or implemented in a variety of ways.

Claims

1. A method for preparing AgCuTi solder, characterized in that: The following steps are involved: After pre-treatment of the titanium foil, the pre-treated titanium foil was placed in the silver electroplating solution and the electroplating current density was controlled to be 0.2A / dm in an environment of 25±2℃. 2 -0.5A / dm 2 After plating for 2h-3h, take it out, clean and dry it to obtain a silver-plated titanium foil; place the silver-plated titanium foil in an electroplating copper solution and control the electroplating current density to 1.2A / dm in an environment of 25±2℃. 2 -1.5A / dm 2 After plating for 50-90 minutes, the plated titanium foil is cleaned and dried to obtain a silver / copper double-layered titanium foil; the plated titanium foil is diffused in a vacuum environment at 600-700°C for 24±2 hours to obtain an AgCuTi solder; The electroplating silver solution is prepared by the following steps: dissolving 200g of sodium thiosulfate in deionized water to obtain a sodium thiosulfate solution; dissolving 40g of silver nitrate and 40g of potassium metabisulfite in deionized water respectively, and pouring the potassium metabisulfite solution into the silver nitrate solution under stirring to obtain a silver metabisulfite mixed solution; Immediately mix the sodium thiosulfate solution and the silver metabisulfite mixed solution under stirring to produce a slightly yellow clear solution, add water to make the volume to 1000 mL, and then filter to obtain the electroplating silver solution; The copper electroplating solution is prepared by the following steps: dissolving 250g of copper sulfate and 40g of glucose in deionized water respectively, slowly adding 38mL of concentrated sulfuric acid to the copper sulfate solution after the copper sulfate solution is cooled and stirring, then adding the glucose solution, mixing evenly, and diluting the volume to 1000mL to obtain the copper electroplating solution.

2. The method for preparing the AgCuTi solder according to claim 1, wherein When the electroplated titanium foil is diffused in a vacuum environment at 600-700°C for 24 hours, the vacuum degree of the vacuum environment is controlled to be 2×10 -3 Pa-5×10 -4 Pa.

3. The method for preparing the AgCuTi solder according to claim 1, wherein The process of pre-treating the titanium foil includes degreasing, alkali washing, pickling and activation in sequence.

4. The method for preparing the AgCuTi solder according to claim 3, wherein: When performing the degreasing, the surface of the titanium foil is wiped with acetone, and the wiped surface of the titanium foil is cleaned with deionized water to obtain a degreased titanium foil; When performing the alkali washing, the degreased titanium foil is placed in a mixed alkali solution in a constant temperature water bath at 70° C. and washed for 15-20 minutes, then taken out and washed with deionized water and dried to obtain the alkali washed titanium foil; When performing the pickling, the titanium foil after alkali washing is placed in a pickling solution at 25° C. and immersed for 2 minutes, then taken out and washed with deionized water and dried to obtain the pickled titanium foil; During the activation, the acid-washed titanium foil was immersed in an activation solution at 25° C. for 5 minutes, then taken out, washed with deionized water, and dried to obtain the activated titanium foil.

5. The method for preparing the AgCuTi solder according to claim 4, wherein: The mixed alkaline solution is prepared by mixing 35g / L sodium hydroxide solution, 35g / L sodium carbonate solution and 35g / L sodium phosphate solution; The pickling solution is prepared by mixing 400 mL / L hydrochloric acid and 65 mL / L hydrofluoric acid; The activation solution is prepared by mixing 120 mL / L hydrofluoric acid and 850 mL / L hydrochloric acid.

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