High uniformity nanodispersion strengthened copper and method of making same

Abstract

The present application relates to a kind of high uniformity nanometer dispersion strengthening copper and its preparation method, which includes screening the metal as dispersion strengthening phase which is more active than copper, preparing nanometer metal particle stock solution by liquid phase reduction process to the metal salt;Add copper salt solution to it, copper is uniformly coated on the surface of nanometer metal particle by displacement reduction reaction, then sequentially washed to neutral and dry treatment, to obtain copper-coated nanoparticle composite powder;Then cooperate with appropriate pure copper powder, after pressing, reduction sintering treatment, obtain high uniformity nanometer dispersion strengthening copper composite material.The preparation method of the present application avoids adding dispersion strengthening phase particles during powder metallurgy pressing, and further overcomes the defects of uneven distribution and easy agglomeration of dispersion strengthening phase, and the dispersion strengthening phase spacing is controllable, with high dispersibility.The mechanical and electrical comprehensive performance of the prepared dispersion strengthening copper is excellent, and the process flow is simple and controllable, low in cost, easy to scale production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal matrix composites, in particular to a high-uniformity nano-dispersive reinforced copper and a preparation method thereof. BACKGROUND

[0002] Copper and copper alloys are key basic materials supporting the development of national economy, people's livelihood, national defense and military industry, etc. As a typical structure and function integrated material, copper alloy needs to have high strength, high plasticity and high conductivity comprehensive service performance. Dispersive reinforced copper is a kind of high-strength and high-conductivity copper-based material with excellent comprehensive performance, which is widely used in electrical, rail transportation, electronic communication and other fields.

[0003] The preparation methods of dispersively reinforced copper alloy include internal oxidation method, powder metallurgy method, mechanical alloying, spray deposition method and chemical deposition method, etc. Among them, the internal oxidation method and the powder metallurgy method are relatively mature and are most widely used. However, the internal oxidation method has problems such as complex process, long production cycle and high cost, and the product quality cannot be accurately controlled. The powder metallurgy method is a low-cost high-performance metal composite material preparation method, but due to the great difference between the dispersively reinforced particles and the copper matrix in size, morphology, physical properties, etc., it is difficult to make the dispersively reinforced phase particles uniformly dispersed, which easily causes segregation, resulting in poor interface bonding between the dispersively reinforced phase / copper matrix and restricting the performance improvement.

[0004] In-situ generation of dispersively reinforced phase or preparation of composite powder of reinforcing phase particles and copper is a feasible solution to solve the dispersion. Patent document CN114921673A discloses a preparation method of nano-oxide particle dispersively reinforced copper, which uses induction melting and melt atomization technology to prepare Zr-4Cu-2O oxide powder with good wettability and close specific gravity to the matrix alloy melt, and then the powder is used as raw material together with the matrix copper metal for melting and casting to prepare kilogram-level ODS-Cu material. Patent document CN103981381A discloses a method for preparing nano-alumina dispersively reinforced copper-based composite material by sol-gel method. The nano-alumina / carbon nanotube and copper composite powder is prepared by using soluble salts of copper and aluminum or adding carbon nanotubes as raw materials, and then the composite powder is isostatic pressing and sintering in hydrogen atmosphere to obtain a dispersively reinforced copper-based composite material with 0.1-3wt.% of nano-alumina.

[0005] The methods disclosed at present mostly use physical methods, which cannot effectively avoid the segregation caused by the difference in physical properties between the dispersively reinforced phase and the copper matrix, and the production process flow, cycle and cost cannot be completely solved, which limits the further development and application of dispersively reinforced copper alloy. SUMMARY

[0006] The present application aims to provide a kind of high uniformity nanometer dispersion strengthened copper and its preparation method, which is based on copper coated nanometer metal particle composite powder, the dispersion strengthened copper prepared by the method provided by the present application has high density, the dispersion strengthened phase has high uniformity, the spacing between dispersion strengthened phase is controllable, and there is a strong interface bonding strength between copper matrix, the phase is single and there is no other impurity pollution.This method avoids the performance deficiency problem caused by process from raw material, the mechanical and electrical comprehensive performance of the prepared dispersion strengthened copper is better than that of traditional method, and the process is simple.

[0007] To this end, the present application provides a kind of preparation method of nanometer dispersion strengthened copper composite material, which comprises the following steps:

[0008] S1, adding reducing agent and surfactant to metal salt solution, to obtain nanometer metal powder stock solution by reaction;

[0009] S2, mix the nanometer metal powder stock solution with copper salt solution, and obtain copper coated nanoparticle composite powder stock solution by displacement reduction reaction;

[0010] S3, the copper coated nanoparticle composite powder stock solution is washed to neutral, dried in turn, to obtain copper coated nanoparticle composite powder;

[0011] S4, mix the copper coated nanoparticle composite powder with pure copper powder, and prepare nanometer dispersion strengthened copper composite material by pressing and reduction sintering in turn.

[0012] Further, in step S1, the metal element of the metal salt has higher activity than copper element.

[0013] Further, the metal salt includes one or more combinations selected from the group consisting of chlorides, sulfates, nitrates or other water-soluble salts of molybdenum (Mo), iron (Fe), chromium (Cr) and manganese (Mn).

[0014] Further, in step S1, the concentration of the metal salt in the metal salt solution is 0.1-5 mol / L, such as 0.1 mol / L, 0.2 mol / L, 0.45 mol / L, 0.5 mol / L, 0.6 mol / L, 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, etc.

[0015] Further, in step S1, the metal salt solution is prepared by dissolving the metal salt in deionized water.

[0016] Further, in step S1, the reducing agent comprises one or more than two combinations selected from the group consisting of KBH4, NaBH4, N2H4-H2O, C6H8O6.

[0017] Further, in step S1, the concentration of the reducing agent is excessive relative to the metal salt. In some embodiments, the concentration of the reducing agent is 0.5-20 mol / L after the reducing agent is added in step S1; for example, 0.5 mol / L, 1 mol / L, 5 mol / L, 10 mol / L, 15 mol / L, 20 mol / L, etc.

[0018] Further, in step S1, the surfactant comprises one or more than two combinations selected from the group consisting of polyvinylpyrrolidone (PVP), benzotriazole (BTA), octylphenol polyoxyethylene ether OP-10, cetyltrimethylammonium bromide (CTAB), disodium ethylenediaminetetraacetate (EDTA-2Na), sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), sodium citrate.

[0019] Further, the concentration of the surfactant is 0.05-10 mol / L after the surfactant is added in step S1; for example, 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.45 mol / L, 0.5 mol / L, 1 mol / L, 5 mol / L, 10 mol / L, etc.

[0020] Further, in step S1, the reaction is carried out under stirring, and the stirring speed is 600-2000 rpm; for example, 600 rpm, 1000 rpm, 1300 rpm, 1600 rpm, 2000 rpm, etc.

[0021] Further, in step S1, the reaction is carried out at a pH value of 5-15; for example, the pH value is 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15; in some embodiments, HCl, NaOH, NH3-H2O, etc. are used to adjust the pH value.

[0022] Further, in step S1, the reaction temperature is 20-100°C; for example, it can be 20°C, 25°C, 30°C, 35°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, etc.

[0023] Further, in step S1, the median particle size of the nano-metal powder particles is 50-900 nm; for example, it is 50 nm, 100 nm, 150 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, etc.

[0024] Further, in step S2, the copper salt includes one or more than two combinations selected from the group consisting of CuSO4·5H2O, CuCl2·2H2O, Cu(NO3)2.

[0025] Further, in step S2, the concentration of the copper salt in the copper salt solution is 0.5-20 mol / L; for example, 0.5 mol / L, 1 mol / L, 2 mol / L, 4 mol / L, 5 mol / L, 10 mol / L, 15 mol / L, 20 mol / L, etc.

[0026] Further, in step S2, the copper salt solution is prepared by dissolving the copper salt in deionized water.

[0027] Further, in step S2, the copper salt is in excess relative to the nano metal powder particles. In some embodiments, the volume ratio of the nano metal powder particle stock solution to the copper salt solution is 5-8:1.

[0028] Further, in step S2, the displacement reduction reaction is carried out under stirring, and the stirring speed is 800-2000 rpm; for example, 800 rpm, 1000 rpm, 1300 rpm, 1600 rpm, 2000 rpm, etc.

[0029] Further, in step S2, the temperature of the displacement reduction reaction is 20-100°C; for example, it can be 20°C, 25°C, 30°C, 35°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, etc.

[0030] Further, in the copper-coated nanoparticle composite powder, the thickness of the copper coating is 0.5-10 μm; for example, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm.

[0031] Further, in step S3, the drying treatment is oven drying; the temperature of the oven drying is 40-80°C; for example, 40°C, 50°C, 60°C, 70°C, 80°C, etc.

[0032] Further, in step S3, the drying is carried out under vacuum.

[0033] Further, in step S4, the pressing is die pressing or cold isostatic pressing; the pressure of the pressing is 100-800 MPa.

[0034] Further, in step S4, the reduction sintering is carried out under a mixed atmosphere of N2 and H2, wherein the ratio of N2 to H2 is 1-5:1-5.

[0035] Further, in step S4, the temperature of the reduction sintering is 700-1350 DEG C, for example, 700 DEG C, 800 DEG C, 1000 DEG C, 1200 DEG C, 1300 DEG C, 1350 DEG C, etc.; the time of the reduction sintering is 1-8h, for example, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, etc.

[0036] In a second aspect of the present application, a nanometer dispersion strengthened copper composite is provided, which is prepared by the method according to the first aspect of the present application.

[0037] Compared with the prior art, the present application has the following beneficial effects:

[0038] In the preparation process of the dispersion strengthened copper alloy, the present application avoids adding dispersion strengthened phase particles during powder metallurgy pressing, thereby avoiding segregation in the mixing process caused by the difference in physical properties between the dispersion strengthened phase and the copper matrix, effectively solving the problems of uneven distribution and easy agglomeration of the dispersion strengthened phase in the copper matrix, and the dispersion strengthened phase spacing is controllable, and the copper matrix has better wettability and bonding strength.

[0039] The present application utilizes the characteristic that copper is less active than the inner core metal, and replaces copper ions with copper atoms coated on the surface of the inner core metal nanoparticles. Even if the copper-coated metal composite powder is unevenly coated, the nanoparticles dispersion strengthened phase in the dispersion strengthened copper alloy formed by powder pressing and sintering can still ensure uniform distribution. The nanoscale dispersion strengthened phase of the present application is controllable and uniform, and the material macroscopic performance is better than that of the traditional preparation method. Moreover, the entire process of the present application is simple and controllable, low in cost, and easy to realize large-scale production. DETAILED DESCRIPTION

[0040] Exemplary embodiments of the present disclosure will be described in greater detail below. It should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be accurately conveyed to those skilled in the art.

[0041] Example 1 Fe-Cu dispersion strengthened copper

[0042] S1: weigh FeCl4H2O and dissolve it in 5L deionized water to make it completely dissolved, and prepare a FeCl aqueous solution with a concentration of 0.45 mol / L; add SDS to the FeCl aqueous solution to make the concentration of SDS 0.45 mol / L, mix and stir for 20 min, slowly add NaOH aqueous solution (concentration of 2.0 mol / L) to adjust the pH to 9; under the action of mechanical stirring at 700 rpm, slowly add 3L NaBH4 aqueous solution with a concentration of 1.115 mol / L, after the addition is completed, warm up to 40℃, and after 30 min of reaction, iron nanoparticles are precipitated to prepare a nano metal powder stock solution;

[0043] S2: weigh CuSO4·5H2O and dissolve it in 1L deionized water to prepare a CuSO4 aqueous solution with a concentration of 4.1 mol / L; add the CuSO4 aqueous solution to the nano metal powder stock solution and stir vigorously at 900 rpm, and continue to react for 30 min at a temperature of 40℃ to prepare a copper-coated nanoparticle composite powder stock solution;

[0044] S3: take the copper-coated nanoparticle composite powder stock solution, centrifuge and wash 5 times at 10000 rpm for 5 min each time, until it is washed to neutral, then vacuum dry the precipitate obtained after washing in a vacuum drying oven at 50℃ for 5h to prepare a copper-coated nanoparticle composite powder;

[0045] S4: crush and sieve the copper-coated nanoparticle composite powder, mix it with pure copper powder with a particle size of 60μm at a mass ratio of 2:3, then weigh 100g of the powder and press it under a pressure of 300MPa, then put the pressed block into a sintering furnace and sinter it at a temperature of 1000℃ for 3h, with a heating rate of 5℃ / min, and a volume ratio of N2 to H2 in the reducing atmosphere being 2:1, after sintering, take out the dispersed strengthened copper after cooling in the furnace.

[0046] Example 2 Cr-Cu dispersed strengthened copper

[0047] S1: weigh Cr(NO3)3·9H2O and dissolve it in 5L deionized water to make it completely dissolved, and prepare a Cr(NO3)3 aqueous solution with a concentration of 0.2 mol / L; add EDTA-2Na to the Cr(NO3)3 aqueous solution to make the concentration of EDTA-2Na 0.2 mol / L, mix and stir for 20 min, add NaOH aqueous solution (concentration of 2.0 mol / L) to adjust the pH to 11; slowly add 2L NaBH4 aqueous solution with a concentration of 1.0 mol / L under the action of mechanical stirring at 900 rpm, after the addition is completed, warm up to 60℃, and after 30 min of reaction, chromium nanoparticles are precipitated to prepare a nano metal powder stock solution;

[0048] S2: CuSO4·5H2O was weighed and dissolved in 1 L of deionized water to prepare a CuSO4 aqueous solution with a concentration of 2.0 mol / L. The CuSO4 aqueous solution was added to the nano-metal powder particle stock solution and stirred vigorously at 1000 rpm. The reaction was continued for 60 min at a temperature of 70°C to prepare a copper-coated nanoparticle composite powder stock solution;

[0049] S3: The copper-coated nanoparticle composite powder stock solution was centrifuged and washed 6 times at 10000 rpm for 5 min each time until it was washed to neutral. The precipitate obtained after washing was then vacuum dried in a vacuum drying oven at 50°C for 5 h to prepare a copper-coated nanoparticle composite powder.

[0050] S4: The copper-coated nanoparticle composite powder was crushed and sieved, and mixed with pure copper powder with a particle size of 65 μm at a mass ratio of 1:4. Then 100 g of the powder was pressed at a pressure of 350 MPa. The pressed block was then placed in a sintering furnace and sintered at a temperature of 1025°C for 3 h at a heating rate of 5°C / min in a reducing atmosphere with a volume ratio of N2 to H2 of 1:1. After sintering, the dispersion strengthened copper was removed from the furnace and cooled to obtain a dispersion strengthened copper.

[0051] Example 3 Mn-Cu dispersion strengthened copper

[0052] S1: MnC4H6O4·4H2O was weighed and dissolved in 3 L of deionized water to prepare a MnC4H6O4 aqueous solution with a concentration of 0.6 mol / L. CTAB was added to the MnC4H6O4 aqueous solution to make the concentration of CTAB 0.3 mol / L. The mixture was stirred for 20 min, and HCl aqueous solution (concentration of 1.0 mol / L) was slowly added to adjust the pH to 5. The mixed aqueous solution was mechanically stirred at a speed of 900 rpm, and 2.5 L of NaBH4 solution with a concentration of 1.25 mol / L was slowly added. After the addition was completed, the temperature was increased to 50°C for reaction. Manganese nanoparticles were precipitated after 30 min of reaction to prepare a nano-metal powder particle stock solution.

[0053] S2: CuSO4·5H2O was weighed and dissolved in 1 L of deionized water to prepare a CuSO4 aqueous solution with a concentration of 1.0 mol / L. The CuSO4 aqueous solution was added to the nano-metal powder particle stock solution and stirred vigorously at 1000 rpm. The reaction was continued for 60 min at a temperature of 80°C to prepare a copper-coated nanoparticle composite powder stock solution;

[0054] S3: Take the copper-coated nanoparticle composite powder stock solution, centrifugal washing 6 times, 8000 rpm centrifugal 5 min each time, until washing to neutral, then the precipitate obtained by washing is placed in a vacuum drying oven and vacuum dried at 50 DEG C for 5 h, to prepare the copper-coated nanoparticle composite powder;

[0055] S4: The copper-coated nanoparticle composite powder is crushed and sieved, mixed with pure copper powder with a particle size of 65 μm at a mass ratio of 3:7, then 100 g of the powder is cold isostatic pressed at a pressure of 300 MPa, then the pressed block is sent into a sintering furnace and sintered at a temperature of 1050 DEG C for 2 h, the heating rate is 5 DEG C / min, the volume ratio of the reducing atmosphere N2 and H2 is 1:2, after sintering, the sintered block is taken out after furnace cooling to obtain dispersion strengthened copper.

[0056] The above only describes the preferred embodiments of the present application, but the protection scope of the present application is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for preparing a nano-dispersion reinforced copper composite material, characterized in that, Includes the following steps: S1. A reducing agent and a surfactant are added to a metal salt solution to react and obtain a nano-metal powder particle stock solution; the reducing agent includes one or more combinations selected from the group consisting of: KBH4, NaBH4, N2H4·H2O, C6H8O6; the surfactant includes one or more combinations selected from the group consisting of: polyvinylpyrrolidone, benzotriazole, octylphenol polyoxyethylene ether OP-10, hexadecyltrimethylammonium bromide, disodium ethylenediaminetetraacetate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, sodium citrate; S2. The nano-metal powder stock solution is mixed with a copper salt solution, and a copper-coated nano-particle composite powder stock solution is obtained through a displacement reduction reaction. S3. The copper-coated nanoparticle composite powder stock solution is washed until neutral and then dried to obtain copper-coated nanoparticle composite powder. S4. The copper-coated nanoparticle composite powder is mixed with pure copper powder and then subjected to pressing and reduction sintering processes to prepare a nano-dispersion reinforced copper composite material.

2. The preparation method according to claim 1, characterized in that, In step S1, the metal element in the metal salt is more reactive than the copper element.

3. The preparation method according to claim 2, characterized in that, The metal salts include one or more combinations selected from the group consisting of chlorides, sulfates, and nitrates of molybdenum, iron, chromium, and manganese.

4. The preparation method according to claim 2, characterized in that, The concentration of the metal salt in the metal salt solution is 0.1~5 mol / L.

5. The preparation method according to claim 1, characterized in that, In step S1, the concentration of the reducing agent is in excess relative to the metal salt.

6. The preparation method according to claim 1, characterized in that, In step S1, the surfactant is added to a concentration of 0.05~10 mol / L.

7. The preparation method according to claim 1, characterized in that, In step S1, the reaction is carried out under stirring conditions, and the stirring speed is 600~2000 rpm.

8. The preparation method according to claim 1, characterized in that, In step S1, the reaction is carried out under conditions where the pH value is 5 to 15.

9. The preparation method according to claim 1, characterized in that, In step S1, the reaction temperature is 20~100℃.

10. The preparation method according to claim 1, characterized in that, In step S2, the copper salt includes one or more combinations selected from the group consisting of CuSO4·5H2O, CuCl2·2H2O, and Cu(NO3)2.

11. The preparation method according to claim 1, characterized in that, The concentration of copper salt in the copper salt solution is 0.5~20 mol / L.

12. The preparation method according to claim 1, characterized in that, In step S2, the displacement-reduction reaction is carried out under stirring conditions, and the stirring speed is 800~2000 rpm.

13. The preparation method according to claim 1, characterized in that, The temperature of the displacement-reduction reaction is 20~100℃.

14. The preparation method according to claim 1, characterized in that, In the copper-coated nanoparticle composite powder, the copper coating thickness is 0.5~10 µm.

15. The preparation method according to claim 1, characterized in that, In step S3, the drying process is called drying; the drying temperature is 40~80℃.

16. The preparation method according to claim 1, characterized in that, In step S4, the pressing is either molding or cold isostatic pressing; the pressing pressure is 100~800MPa.

17. The preparation method according to claim 1, characterized in that, In step S4, the reduction sintering is carried out in a mixed atmosphere of N2 and H2, wherein the ratio of N2 to H2 is 1~5:1~5.

18. The preparation method according to claim 1, characterized in that, In step S4, the reduction sintering temperature is 700~1350℃, and the reduction sintering time is 1~8 h.

19. A nano-dispersion reinforced copper composite material, characterized in that, The nano-dispersion reinforced copper composite material is prepared according to the preparation method described in any one of claims 1 to 18.