A preparation method for improving the electrical conductivity of Cu-Ni-Si composite materials

Abstract

The invention discloses a preparation method for improving the electrical conductivity of a Cu-Ni-Si composite material, the steps comprising: (1) preparing a composite aqueous solution of nickel chloride and sodium iodide; sieving copper powder, degreasing, removing oxide skin, and then treating with a composite aqueous solution of nickel chloride and sodium iodide to obtain activated copper powder; (2) palladium plating on the surface to obtain palladium-plated powder; (3) treating with a silver ammonia solution to obtain a modified copper powder; (4) ball-milling a mixture of modified copper powder, nickel powder and silicon powder, and hot pressing and sintering molding, the hot pressing and sintering parameters being: a pressure of 30MPa, a sintering temperature of 960°C, and a sintering time of 1h; then solid solutioning at 900°C for 2h, water cooling to room temperature after solid solutioning, aging at 450°C for 3h, and air cooling to room temperature after aging treatment to obtain a Cu-Ni-Si composite material. The Cu-Ni-Si composite material prepared by the method of the present invention can significantly improve the electrical conductivity and surface hardness of the Cu-Ni-Si material and improve the comprehensive performance of the material.

Description

Technical Field

[0001] The present invention relates to the technical field of Cu-Ni-Si composite materials, and particularly to a preparation method for improving the electrical conductivity of Cu-Ni-Si composite materials. Background Art

[0002] With the rapid development of information technology, integrated circuits are developing towards large-scale and high-integration, posing higher requirements for the strength and conductivity of materials. Especially in the electronics industry, conductive elastic components are developing towards miniaturization and high performance. Although pure copper has good electrical conductivity, its hardness and strength are relatively low, restricting its scope of use. By adding alloying elements and combining different strengthening mechanisms, such as solid solution strengthening, aging strengthening, work hardening, etc., copper alloys with good mechanical properties and electrical conductivity are designed and prepared. Among them, age-hardening copper alloys have become the research focus due to their good comprehensive properties. Cu-Ni-Si composite material is an age-hardening copper alloy. By adding Ni and Si into the Cu matrix, a supersaturated solid solution is formed through solution treatment, and then through aging treatment, Ni and Si atoms precipitate from the supersaturated solid solution in the form of Ni 2 Si. The precipitated phase can hinder the movement of dislocations, thereby effectively increasing the hardness of the copper alloy. However, since Ni and Cu have similar crystal structures and can be completely miscible, while Si has a large scattering effect on free electrons in the matrix, which will significantly reduce the electrical conductivity of the composite material. It is necessary to optimize and improve the alloy composition and preparation process of the material. Summary of the Invention

[0003] Therefore, the present invention provides a preparation method for improving the electrical conductivity of Cu-Ni-Si composite materials. The steps include:

[0004] (1) Prepare a composite aqueous solution of nickel chloride and sodium iodide; pass copper powder through a 1000-mesh sieve, collect the sieved powder, soak the sieved powder in acetone for more than 10 minutes, then perform solid-liquid separation, dry the solid phase powder at 80°C for more than 30 minutes, soak the dried powder in dilute hydrochloric acid solution for more than 8 minutes, then perform solid-liquid separation, wash the solid phase with deionized water to remove the residual acid solution, dry at 80°C for more than 30 minutes, soak the dried solid phase in the composite aqueous solution of nickel chloride and sodium iodide to form a suspension; keep the suspension at a constant temperature of 90±2°C in a water bath for more than 10 minutes, and perform condensation reflux during the heat preservation process; after the heat preservation is completed, perform solid-liquid separation, wash the solid phase with deionized water more than 3 times, and then dry at 80°C for more than 30 minutes to obtain activated copper powder;

[0005] (2) Prepare a mixed aqueous solution of palladium chloride, disodium ethylenediaminetetraacetate, sodium citrate, ammonium chloride, and glycine as the palladium plating solution; immerse the activated copper powder in the palladium plating solution to form a suspension, stir the suspension, add ammonia water to adjust the pH to 8; then keep the suspension at a constant temperature of 60±2°C in a water bath for heat preservation, add sodium hypophosphite, and continue to stir the suspension in a water bath at 60±2°C for 60-80 min after the feeding is completed. Then, perform solid-liquid separation, wash the solid phase with deionized water more than 3 times, and then dry it at 80°C for more than 30 min to obtain palladium-plated powder;

[0006] (3) Prepare a mixed solution of catechol and diethylenetriamine, add the mixed solution of catechol and diethylenetriamine to 1M Tris-HCl buffer solution to form a mixed solution, add concentrated hydrochloric acid to the mixed solution to adjust the pH to 8.5, and then add the palladium-plated powder to the mixed solution. Stir the mixed solution for 5-6 h after the feeding, then perform solid-liquid separation, wash the solid phase with deionized water more than 3 times, dry it at 80°C for more than 30 min. Add the dried solid phase to the silver ammonia solution, stir the solution after the feeding, and then dropwise add glucose solution to the solution under stirring. Continue to stir the solution for more than 20 min after the feeding is completed, then perform solid-liquid separation, wash the solid phase with deionized water more than 3 times, and dry it at 80°C for more than 30 min to obtain modified copper powder;

[0007] (4) Ball-mill and mix the modified copper powder, nickel powder, and silicon powder evenly to obtain a mixed powder; hot-press and sinter the mixed powder into a shape in a hot-press furnace, then perform solution treatment at 900°C for 2 h, cool it to room temperature in water after solution treatment, perform aging treatment at 450°C for 3-4 h, and air-cool it to room temperature after aging treatment to obtain a Cu-Ni-Si composite material.

[0008] Further, in the step (1), in the composite aqueous solution of nickel chloride and sodium iodide, the concentration of nickel chloride is 18-20 g / L, the concentration of sodium iodide is 600-700 g / L, and the solvent is water; the solid-liquid mass ratio of the solid phase immersed in the composite aqueous solution of nickel chloride and sodium iodide to form a suspension is solid phase: composite aqueous solution of nickel chloride and sodium iodide = 1:100.

[0009] Further, in the step (2), the concentrations of each component in the palladium plating solution are: palladium chloride 0.05-0.06 g / 100 mL; disodium ethylenediaminetetraacetate 1.0-1.2 g / 100 mL; sodium citrate 0.6-0.8 g / 100 mL; ammonium chloride 0.04-0.05 g / 100 mL; glycine 0.01-0.03 g / 100 mL; the solvent is water; the solid-liquid ratio of the activated copper powder immersed in the palladium plating solution is activated copper powder: palladium plating solution = 1 g / 100 mL, the mass percentage of the solute in the ammonia water is 25%; the mass ratio of the added sodium hypophosphite to the mass of the activated copper powder added to the palladium plating solution is sodium hypophosphite: activated copper powder = 0.3-0.4:1.

[0010] Further, in the step (3), in the catechol and diethylenetriamine mixed solution, the concentration of catechol is 6-8 g / L, the concentration of diethylenetriamine is 20-24 g / L, and the solvent is water; the volume ratio of the catechol and diethylenetriamine mixed solution to the Tris-HCl buffer solution added is catechol and diethylenetriamine mixed solution:Tris-HCl buffer solution = 1:10; the mass ratio of the palladium-plated powder added to the mixed solution is palladium-plated powder:mixed solution = 1:50.

[0011] Further, in the step (3), in the silver ammonia solution, the molar concentration of silver is 0.08-0.09 mol / L, and the pH is 11; the solid-liquid mass ratio of the dried solid phase added to the silver ammonia solution is dried solid phase:silver ammonia solution = 1:100; the concentration of glucose in the glucose solution is 20 g / L, and the solvent is water; the volume ratio of the glucose solution to the silver ammonia solution added dropwise is glucose solution:silver ammonia solution = 1:10.

[0012] Further, in the step (4), the mass ratio of the modified copper powder, nickel powder and silicon powder is modified copper powder:nickel powder:silicon powder = 95:4:1; both the nickel powder and the silicon powder are powders passing through a 1000-mesh sieve.

[0013] Further, in the step (4), the ball milling process parameters are: the ball-to-material mass ratio is ball:material = 1.5:1; the rotation speed is 120 r / min, and the ball milling time is 10 h; the hot pressing and sintering parameters are: the pressure is 30 MPa, the sintering temperature is 960 °C, and the sintering time is 1 h.

[0014] The beneficial effect of the present invention lies in that: the Cu-Ni-Si composite material prepared by the method of the present invention can significantly improve the electrical conductivity and surface hardness of the Cu-Ni-Si material, and improve the comprehensive performance of the material. Specific embodiments

[0015] The following further illustrates the present invention with reference to embodiments.

[0016] Example 1

[0017] A preparation method for improving the electrical conductivity of a Cu-Ni-Si composite material, the steps including:

[0018] (1) Prepare a composite aqueous solution of nickel chloride and sodium iodide. In the composite aqueous solution of nickel chloride and sodium iodide, the concentration of nickel chloride is 18 g / L, the concentration of sodium iodide is 600 g / L, and the solvent is water. Pass copper powder through a 1000-mesh sieve, collect the sieved powder, soak the sieved powder in acetone for 10 min for degreasing, then perform solid-liquid separation, dry the solid-phase powder at 80 °C for 30 min, soak the dried powder in a dilute hydrochloric acid solution for 8 min to remove the oxide scale, and the mass percentage of the solute in the dilute hydrochloric acid is 5%. Then perform solid-liquid separation, wash the solid phase with deionized water to remove the residual acid solution, dry at 80 °C for 30 min, and soak the dried solid phase in the composite aqueous solution of nickel chloride and sodium iodide to form a suspension. The solid-liquid mass ratio of the solid phase soaked in the composite aqueous solution of nickel chloride and sodium iodide to form the suspension is solid phase: composite aqueous solution of nickel chloride and sodium iodide = 1:100. Keep the suspension in a water bath at a constant temperature of 90 ± 2 °C for 10 min, with condensation reflux during the insulation process. After the insulation ends, perform solid-liquid separation, wash the solid phase with deionized water 3 times, and then dry at 80 °C for 30 min to obtain activated copper powder;

[0019] (2) Prepare a mixed aqueous solution of palladium chloride, disodium ethylenediaminetetraacetate, sodium citrate, ammonium chloride, and glycine as the palladium plating solution. The concentrations of each component in the palladium plating solution are: palladium chloride 0.05 g / 100 mL; disodium ethylenediaminetetraacetate 1.0 g / 100 mL; sodium citrate 0.6 g / 100 mL; ammonium chloride 0.04 g / 100 mL; glycine 0.01 g / 100 mL; and the solvent is water. Soak the activated copper powder in the palladium plating solution to form a suspension. The solid-liquid ratio of the activated copper powder soaked in the palladium plating solution is activated copper powder: palladium plating solution = 1 g / 100 mL. Stir the suspension, add ammonia water to adjust the pH to 8. The mass percentage of the solute in the ammonia water is 25%. Then keep the suspension in a water bath at a constant temperature of 60 ± 2 °C for insulation, add sodium hypophosphite, and the mass ratio of the added sodium hypophosphite to the mass of the activated copper powder added to the palladium plating solution is sodium hypophosphite: activated copper powder = 0.3:1. After adding the materials, continue to keep the suspension in a water bath at 60 ± 2 °C and stir for 60 min, then perform solid-liquid separation, wash the solid phase with deionized water 3 times, and then dry at 80 °C for 30 min to obtain palladium-plated powder;

[0020] (3) Prepare a catechol and diethylenetriamine mixed solution. In the catechol and diethylenetriamine mixed solution, the concentration of catechol is 6 g / L, the concentration of diethylenetriamine is 20 g / L, and the solvent is water. Add the catechol and diethylenetriamine mixed solution into a 1 M Tris-HCl buffer solution to form a mixed solution. The volume ratio of the catechol and diethylenetriamine mixed solution added to the Tris-HCl buffer solution is catechol and diethylenetriamine mixed solution:Tris-HCl buffer solution = 1:10. Adjust the pH of the mixed solution to 8.5 by adding concentrated hydrochloric acid (37 wt%). Then add the palladium-plated powder to the mixed solution. The mass ratio of the palladium-plated powder added to the mixed solution is palladium-plated powder:mixed solution = 1:50. After adding the materials, stir the mixed solution for 5 h, then perform solid-liquid separation. Wash the solid phase with deionized water 3 times, dry it at 80 °C for 30 min. Add the dried solid phase into a silver ammonia solution. In the silver ammonia solution, the molar concentration of silver is 0.08 mol / L and the pH is 11. The mass ratio of the dried solid phase added to the silver ammonia solution is dried solid phase:silver ammonia solution = 1:100. After adding the materials, stir the solution, and then dropwise add a glucose solution to the solution under stirring. In the glucose solution, the concentration of glucose is 20 g / L and the solvent is water. The volume ratio of the glucose solution dropwise added to the silver ammonia solution is glucose solution:silver ammonia solution = 1:10. After the addition is completed, continue to stir the solution for 20 min, then perform solid-liquid separation. Wash the solid phase with deionized water 3 times, dry it at 80 °C for 30 min to obtain modified copper powder.

[0021] (4) Ball-mill and mix the modified copper powder, nickel powder, and silicon powder evenly to obtain a mixed powder. The mass ratio of the modified copper powder, nickel powder, and silicon powder is modified copper powder:nickel powder:silicon powder = 95:4:1. Both the nickel powder and the silicon powder are powders passing through a 1000-mesh sieve. The ball-milling process parameters are: the ball-to-material mass ratio is ball:material = 1.5:1; the rotation speed is 120 r / min, and the ball-milling time is 10 h. The mixed powder is hot-pressed and sintered into shape in a hot-pressing furnace. The hot-pressing sintering parameters are: the pressure is 30 MPa, the sintering temperature is 960 °C, and the sintering time is 1 h. Then perform solution treatment at 900 °C for 2 h, cool it to room temperature with water after solution treatment, perform aging treatment at 450 °C for 3 h, and air-cool it to room temperature after aging treatment to obtain a Cu-Ni-Si composite material.

[0022] Example 2

[0023] A preparation method for improving the electrical conductivity of a Cu-Ni-Si composite material, the steps include:

[0024] (1) Prepare a composite aqueous solution of nickel chloride and sodium iodide. In the composite aqueous solution of nickel chloride and sodium iodide, the concentration of nickel chloride is 19 g / L, the concentration of sodium iodide is 650 g / L, and the solvent is water. Pass copper powder through a 1000-mesh sieve, collect the sieved powder, soak the sieved powder in acetone for 10 minutes to remove oil, then perform solid-liquid separation, dry the solid phase powder at 80 °C for 30 minutes, soak the dried powder in a dilute hydrochloric acid solution for 8 minutes to remove the oxide scale, and the mass percentage of the solute in the dilute hydrochloric acid is 5%. Then perform solid-liquid separation, wash the solid phase with deionized water to remove the residual acid solution, dry at 80 °C for 30 minutes, soak the dried solid phase in the composite aqueous solution of nickel chloride and sodium iodide to form a suspension, and the solid-liquid mass ratio of the solid phase soaked in the composite aqueous solution of nickel chloride and sodium iodide to form the suspension is solid phase: composite aqueous solution of nickel chloride and sodium iodide = 1:100. Keep the suspension in a water bath at a constant temperature of 90 ± 2 °C for 10 minutes, and perform condensation reflux during the heat preservation process. After the heat preservation is completed, perform solid-liquid separation, wash the solid phase with deionized water 3 times, and then dry at 80 °C for 30 minutes to obtain activated copper powder;

[0025] (2) Prepare a mixed aqueous solution of palladium chloride, disodium ethylenediaminetetraacetate, sodium citrate, ammonium chloride, and glycine as the palladium plating solution. The concentrations of each component in the palladium plating solution are: palladium chloride 0.05 g / 100 mL; disodium ethylenediaminetetraacetate 1.1 g / 100 mL; sodium citrate 0.7 g / 100 mL; ammonium chloride 0.04 g / 100 mL; glycine 0.02 g / 100 mL; and the solvent is water. Soak the activated copper powder in the palladium plating solution to form a suspension. The solid-liquid ratio of the activated copper powder soaked in the palladium plating solution is activated copper powder: palladium plating solution = 1 g / 100 mL. Stir the suspension, add ammonia water to adjust the pH to 8. The mass percentage of the solute in the ammonia water is 25%. Then keep the suspension in a water bath at a constant temperature of 60 ± 2 °C for heat preservation, add sodium hypophosphite, and the mass ratio of the added sodium hypophosphite to the mass of the activated copper powder added to the palladium plating solution is sodium hypophosphite: activated copper powder = 0.3:1. After the feeding is completed, continue to keep the suspension in a water bath at a constant temperature of 60 ± 2 °C and stir for 60 minutes, then perform solid-liquid separation, wash the solid phase with deionized water 3 times, and then dry at 80 °C for 30 minutes to obtain palladium-plated powder;

[0026] (3) Prepare a catechol and diethylenetriamine mixed solution. In the catechol and diethylenetriamine mixed solution, the concentration of catechol is 7 g / L, the concentration of diethylenetriamine is 22 g / L, and the solvent is water. Add the catechol and diethylenetriamine mixed solution into 1 M Tris-HCl buffer solution to form a mixed solution. The volume ratio of the catechol and diethylenetriamine mixed solution to the Tris-HCl buffer solution is catechol and diethylenetriamine mixed solution:Tris-HCl buffer solution = 1:10. Adjust the pH of the mixed solution to 8.5 with concentrated hydrochloric acid (37 wt%). Then add the palladium-plated powder to the mixed solution. The mass ratio of the palladium-plated powder to the mixed solution is palladium-plated powder:mixed solution = 1:50. After adding the materials, stir the mixed solution for 5 h, then perform solid-liquid separation. Wash the solid phase with deionized water 3 times, dry it at 80 °C for 30 min. Add the dried solid phase into silver ammonia solution. In the silver ammonia solution, the molar concentration of silver is 0.08 mol / L and the pH is 11. The mass ratio of the dried solid phase to the silver ammonia solution is dried solid phase:silver ammonia solution = 1:100. After adding the materials, stir the solution, and then dropwise add glucose solution to the solution under stirring. The concentration of glucose in the glucose solution is 20 g / L and the solvent is water. The volume ratio of the glucose solution to the silver ammonia solution is glucose solution:silver ammonia solution = 1:10. After adding the materials, continue to stir the solution for 20 min, then perform solid-liquid separation. Wash the solid phase with deionized water 3 times, dry it at 80 °C for 30 min to obtain modified copper powder;

[0027] (4) Ball-mill and mix the modified copper powder, nickel powder and silicon powder evenly to obtain a mixed powder. The mass ratio of the modified copper powder, nickel powder and silicon powder is modified copper powder:nickel powder:silicon powder = 95:4:1. Both the nickel powder and the silicon powder are powders passing through a 1000-mesh sieve. The ball-milling process parameters are: the mass ratio of balls to materials is balls:materials = 1.5:1; the rotation speed is 120 r / min, and the ball-milling time is 10 h. The mixed powder is hot-pressed and sintered into shape in a hot-pressing furnace. The hot-pressing sintering parameters are: the pressure is 30 MPa, the sintering temperature is 960 °C, and the sintering time is 1 h. Then perform solution treatment at 900 °C for 2 h, cool it to room temperature with water after solution treatment, perform aging treatment at 450 °C for 3 h, and air-cool it to room temperature after aging treatment to obtain Cu-Ni-Si composite material.

[0028] Example 3

[0029] A preparation method for improving the electrical conductivity of Cu-Ni-Si composite material, the steps include:

[0030] (1) Prepare a composite aqueous solution of nickel chloride and sodium iodide. In the composite aqueous solution of nickel chloride and sodium iodide, the concentration of nickel chloride is 19 g / L, the concentration of sodium iodide is 650 g / L, and the solvent is water. Pass copper powder through a 1000-mesh sieve, collect the sieved powder, soak the sieved powder in acetone for 10 min for degreasing, then perform solid-liquid separation, dry the solid phase powder at 80 °C for 30 min, soak the dried powder in a dilute hydrochloric acid solution for 8 min to remove the oxide scale, and the mass percentage of the solute in the dilute hydrochloric acid is 5%. Then perform solid-liquid separation, wash the solid phase with deionized water to remove the residual acid solution, dry it at 80 °C for 30 min, and soak the dried solid phase in the composite aqueous solution of nickel chloride and sodium iodide to form a suspension. The solid-liquid mass ratio of the solid phase soaked in the composite aqueous solution of nickel chloride and sodium iodide to form the suspension is solid phase: composite aqueous solution of nickel chloride and sodium iodide = 1:100. Keep the suspension in a water bath at a constant temperature of 90 ± 2 °C for 10 min, and perform condensation reflux during the heat preservation process. After the heat preservation is completed, perform solid-liquid separation, wash the solid phase with deionized water 3 times, and then dry it at 80 °C for 30 min to obtain activated copper powder;

[0031] (2) Prepare a mixed aqueous solution of palladium chloride, disodium ethylenediaminetetraacetate, sodium citrate, ammonium chloride, and glycine as the palladium plating solution. The concentrations of each component in the palladium plating solution are: palladium chloride 0.06 g / 100 mL; disodium ethylenediaminetetraacetate 1.1 g / 100 mL; sodium citrate 0.7 g / 100 mL; ammonium chloride 0.05 g / 100 mL; glycine 0.02 g / 100 mL; and the solvent is water. Soak the activated copper powder in the palladium plating solution to form a suspension. The solid-liquid ratio of the activated copper powder soaked in the palladium plating solution is activated copper powder: palladium plating solution = 1 g / 100 mL. Stir the suspension, add ammonia water to adjust the pH to 8. The mass percentage of the solute in the ammonia water is 25%. Then keep the suspension in a water bath at a constant temperature of 60 ± 2 °C for heat preservation, add sodium hypophosphite, and the mass ratio of the added sodium hypophosphite to the mass of the activated copper powder added to the palladium plating solution is sodium hypophosphite: activated copper powder = 0.4:1. After the feeding is completed, continue to keep the suspension in a water bath at 60 ± 2 °C and stir it for 60 min, then perform solid-liquid separation, wash the solid phase with deionized water 3 times, and then dry it at 80 °C for 30 min to obtain palladium-plated powder;

[0032] (3) Prepare a catechol and diethylenetriamine mixed solution. In the catechol and diethylenetriamine mixed solution, the concentration of catechol is 7 g / L, the concentration of diethylenetriamine is 22 g / L, and the solvent is water. Add the catechol and diethylenetriamine mixed solution to 1 M Tris-HCl buffer solution to form a mixed solution. The volume ratio of the catechol and diethylenetriamine mixed solution added to the Tris-HCl buffer solution is catechol and diethylenetriamine mixed solution:Tris-HCl buffer solution = 1:10. Adjust the pH of the mixed solution to 8.5 by adding concentrated hydrochloric acid (37 wt%). Then add the palladium-plated powder to the mixed solution. The mass ratio of the palladium-plated powder added to the mixed solution is palladium-plated powder:mixed solution = 1:50. After adding the materials, stir the mixed solution for 5 h, then perform solid-liquid separation. Wash the solid phase with deionized water 3 times, dry it at 80 °C for 30 min. Add the dried solid phase to the silver ammonia solution. In the silver ammonia solution, the molar concentration of silver is 0.09 mol / L and the pH is 11. The mass ratio of the dried solid phase added to the silver ammonia solution is dried solid phase:silver ammonia solution = 1:100. After adding the materials, stir the solution, and then dropwise add the glucose solution to the solution under stirring. The concentration of glucose in the glucose solution is 20 g / L and the solvent is water. The volume ratio of the glucose solution dropped to the silver ammonia solution is glucose solution:silver ammonia solution = 1:10. After adding the materials, continue to stir the solution for 20 min, then perform solid-liquid separation. Wash the solid phase with deionized water 3 times, dry it at 80 °C for 30 min to obtain modified copper powder;

[0033] (4) Ball-mill and mix the modified copper powder, nickel powder and silicon powder evenly to obtain a mixed powder. The mass ratio of the modified copper powder, nickel powder and silicon powder is modified copper powder:nickel powder:silicon powder = 95:4:1. Both the nickel powder and the silicon powder are powders passing through a 1000-mesh sieve. The ball-milling process parameters are: the mass ratio of balls to materials is balls:materials = 1.5:1; the rotation speed is 120 r / min, and the ball-milling time is 10 h. The mixed powder is hot-pressed and sintered into shape in a hot-pressing furnace. The hot-pressing sintering parameters are: the pressure is 30 MPa, the sintering temperature is 960 °C, and the sintering time is 1 h. Then perform solution treatment at 900 °C for 2 h, cool it to room temperature with water after solution treatment, perform aging treatment at 450 °C for 3 h, and air-cool it to room temperature after aging treatment to obtain the Cu-Ni-Si composite material.

[0034] Example 4

[0035] A preparation method for improving the electrical conductivity of Cu-Ni-Si composite materials, the steps include:

[0036] (1) Prepare a composite aqueous solution of nickel chloride and sodium iodide; in the composite aqueous solution of nickel chloride and sodium iodide, the concentration of nickel chloride is 20 g / L, the concentration of sodium iodide is 700 g / L, and the solvent is water; pass copper powder through a 1000-mesh sieve, collect the sieved powder, soak the sieved powder in acetone for 10 min for degreasing, then perform solid-liquid separation, dry the solid-phase powder at 80 °C for 30 min, soak the dried powder in a dilute hydrochloric acid solution for 8 min to remove the oxide scale, and the mass percentage of the solute in the dilute hydrochloric acid is 5%; then perform solid-liquid separation, wash the solid phase with deionized water to remove the residual acid solution, dry at 80 °C for 30 min, soak the dried solid phase in the composite aqueous solution of nickel chloride and sodium iodide to form a suspension, and the solid-liquid mass ratio of the solid phase soaked in the composite aqueous solution of nickel chloride and sodium iodide to form the suspension is solid phase: composite aqueous solution of nickel chloride and sodium iodide = 1:100; keep the suspension in a water bath at a constant temperature of 90 ± 2 °C for 10 min, and perform condensation reflux during the heat preservation process; after the heat preservation is completed, perform solid-liquid separation, wash the solid phase with deionized water 3 times, and then dry at 80 °C for 30 min to obtain activated copper powder;

[0037] (2) Prepare a mixed aqueous solution of palladium chloride, disodium ethylenediaminetetraacetate, sodium citrate, ammonium chloride, and glycine as a palladium plating solution. The concentrations of each component in the palladium plating solution are: palladium chloride 0.06 g / 100 mL; disodium ethylenediaminetetraacetate 1.2 g / 100 mL; sodium citrate 0.8 g / 100 mL; ammonium chloride 0.05 g / 100 mL; glycine 0.03 g / 100 mL; the solvent is water; soak the activated copper powder in the palladium plating solution to form a suspension. The solid-liquid ratio of the activated copper powder soaked in the palladium plating solution is activated copper powder: palladium plating solution = 1 g / 100 mL. Stir the suspension, add ammonia water to adjust the pH to 8; the mass percentage of the solute in the ammonia water is 25%; then keep the suspension in a water bath at a constant temperature of 60 ± 2 °C for heat preservation, add sodium hypophosphite, and the mass ratio of the added sodium hypophosphite to the mass of the activated copper powder added to the palladium plating solution is sodium hypophosphite: activated copper powder = 0.4:1; after the feeding is completed, continue to keep the suspension in a water bath at a constant temperature of 60 ± 2 °C and stir for 60 min, then perform solid-liquid separation, wash the solid phase with deionized water 3 times, and then dry at 80 °C for 30 min to obtain palladium-plated powder;

[0038] (3) Prepare a catechol and diethylenetriamine mixed solution. In the catechol and diethylenetriamine mixed solution, the concentration of catechol is 8 g / L, the concentration of diethylenetriamine is 24 g / L, and the solvent is water. Add the catechol and diethylenetriamine mixed solution to 1 M Tris-HCl buffer to form a mixed solution. The volume ratio of the catechol and diethylenetriamine mixed solution added to the Tris-HCl buffer is catechol and diethylenetriamine mixed solution:Tris-HCl buffer = 1:10. Adjust the pH of the mixed solution to 8.5 with concentrated hydrochloric acid (37 wt%), and then add the palladium-plated powder to the mixed solution. The mass ratio of the palladium-plated powder added to the mixed solution is palladium-plated powder:mixed solution = 1:50. After adding the materials, stir the mixed solution for 5 h, then perform solid-liquid separation. Wash the solid phase with deionized water 3 times, dry it at 80 °C for 30 min. Add the dried solid phase to the silver ammonia solution. In the silver ammonia solution, the molar concentration of silver is 0.09 mol / L and the pH is 11. The mass ratio of the dried solid phase added to the silver ammonia solution is dried solid phase:silver ammonia solution = 1:100. After adding the materials, stir the solution, and then dropwise add the glucose solution to the solution under stirring. The concentration of glucose in the glucose solution is 20 g / L and the solvent is water. The volume ratio of the glucose solution dropwise added to the silver ammonia solution is glucose solution:silver ammonia solution = 1:10. After adding the materials, continue to stir the solution for 20 min, then perform solid-liquid separation. Wash the solid phase with deionized water 3 times, dry it at 80 °C for 30 min to obtain modified copper powder;

[0039] (4) Ball-mill and mix the modified copper powder, nickel powder and silicon powder evenly to obtain a mixed powder. The mass ratio of the modified copper powder, nickel powder and silicon powder is modified copper powder:nickel powder:silicon powder = 95:4:1. Both the nickel powder and the silicon powder are powders passing through a 1000-mesh sieve. The ball-milling process parameters are: the ball-to-material mass ratio is ball:material = 1.5:1; the rotation speed is 120 r / min, and the ball-milling time is 10 h. The mixed powder is hot-pressed and sintered into shape in a hot-pressing furnace. The hot-pressing sintering parameters are: the pressure is 30 MPa, the sintering temperature is 960 °C, and the sintering time is 1 h. Then perform solution treatment at 900 °C for 2 h, cool it to room temperature with water after solution treatment, perform aging treatment at 450 °C for 3 h, and air-cool it to room temperature after aging treatment to obtain a Cu-Ni-Si composite material.

[0040] Comparative Example 1

[0041] A comparative method, the steps include:

[0042] (1) Pass the copper powder through a 1000-mesh sieve, collect the sieved powder, soak the sieved powder in acetone for 10 minutes to remove oil, then separate the solid and liquid, dry the solid-phase powder at 80 °C for 30 minutes, soak the dried powder in a dilute hydrochloric acid solution for 8 minutes to remove the oxide scale, and the mass percentage of the solute in the dilute hydrochloric acid is 5%; then separate the solid and liquid, wash the solid phase with deionized water to remove the residual acid solution, and dry it at 80 °C for 30 minutes to obtain the pre-treated copper powder for this comparative example;

[0043] (2) Prepare a mixed aqueous solution of palladium chloride, disodium ethylenediaminetetraacetate, sodium citrate, ammonium chloride, and glycine as the palladium plating solution. The concentrations of each component in the palladium plating solution are: palladium chloride 0.05 g / 100 mL; disodium ethylenediaminetetraacetate 1.1 g / 100 mL; sodium citrate 0.7 g / 100 mL; ammonium chloride 0.04 g / 100 mL; glycine 0.02 g / 100 mL; the solvent is water; soak the pre-treated copper powder in the palladium plating solution to form a suspension. The solid-liquid ratio of the pre-treated copper powder soaked in the palladium plating solution is pre-treated copper powder:palladium plating solution = 1 g / 100 mL. Stir the suspension, add ammonia water to the suspension to adjust the pH to 8; the mass percentage of the solute in the ammonia water is 25%; then keep the suspension at a constant temperature in a water bath at 60 ± 2 °C for heat preservation, add sodium hypophosphite, and the mass ratio of the added sodium hypophosphite to the mass of the pre-treated copper powder added to the palladium plating solution is sodium hypophosphite:pre-treated copper powder = 0.3:1; after the feeding is completed, continue to keep the suspension at a constant temperature in a water bath at 60 ± 2 °C and stir for 60 minutes, then separate the solid and liquid, wash the solid phase with deionized water 3 times, and then dry it at 80 °C for 30 minutes to obtain the palladium-plated powder;

[0044] (3) Prepare a catechol and diethylenetriamine mixed solution. In the catechol and diethylenetriamine mixed solution, the concentration of catechol is 7 g / L, the concentration of diethylenetriamine is 22 g / L, and the solvent is water. Add the catechol and diethylenetriamine mixed solution to 1 M Tris-HCl buffer to form a mixed solution. The volume ratio of the catechol and diethylenetriamine mixed solution added to the Tris-HCl buffer is catechol and diethylenetriamine mixed solution:Tris-HCl buffer = 1:10. Adjust the pH of the mixed solution to 8.5 with concentrated hydrochloric acid (37 wt%). Then add the palladium-plated powder to the mixed solution. The mass ratio of the palladium-plated powder added to the mixed solution is palladium-plated powder:mixed solution = 1:50. After adding the materials, stir the mixed solution for 5 h, then perform solid-liquid separation. Wash the solid phase with deionized water 3 times, dry it at 80 °C for 30 min. Add the dried solid phase to silver ammonia solution. In the silver ammonia solution, the molar concentration of silver is 0.08 mol / L and the pH is 11. The mass ratio of the dried solid phase added to the silver ammonia solution is dried solid phase:silver ammonia solution = 1:100. After adding the materials, stir the solution, and then dropwise add glucose solution to the solution under stirring. The concentration of glucose in the glucose solution is 20 g / L and the solvent is water. The volume ratio of the glucose solution dropped to the silver ammonia solution is glucose solution:silver ammonia solution = 1:10. After adding the materials, continue to stir the solution for 20 min, then perform solid-liquid separation. Wash the solid phase with deionized water 3 times, dry it at 80 °C for 30 min to obtain the modified copper powder of this comparative example.

[0045] (4) Ball-mill and mix the modified copper powder, nickel powder, and silicon powder evenly to obtain a mixed powder. The mass ratio of the modified copper powder, nickel powder, and silicon powder is modified copper powder:nickel powder:silicon powder = 95:4:1. Both the nickel powder and the silicon powder are powders passing through a 1000-mesh sieve. The ball-milling process parameters are: the ball-to-material mass ratio is ball:material = 1.5:1; the rotation speed is 120 r / min, and the ball-milling time is 10 h. The mixed powder is hot-pressed and sintered into shape in a hot-pressing furnace. The hot-pressing sintering parameters are: the pressure is 30 MPa, the sintering temperature is 960 °C, and the sintering time is 1 h. Then perform solution treatment at 900 °C for 2 h, cool it to room temperature with water after solution treatment, perform aging treatment at 450 °C for 3 h, and air-cool it to room temperature after aging treatment to obtain the Cu-Ni-Si composite material.

[0046] Comparative Example 2

[0047] A method for comparison, the steps include:

[0048] (1) Prepare a composite aqueous solution of nickel chloride and sodium iodide. In the composite aqueous solution of nickel chloride and sodium iodide, the concentration of nickel chloride is 19 g / L, the concentration of sodium iodide is 650 g / L, and the solvent is water. Pass copper powder through a 1000-mesh sieve, collect the sieved powder, soak the sieved powder in acetone for 10 min to remove oil, then separate the solid and liquid phases. Dry the solid phase powder at 80 °C for 30 min. Soak the dried powder in a dilute hydrochloric acid solution for 8 min to remove the oxide scale. The mass percentage of the solute in the dilute hydrochloric acid is 5%. Then separate the solid and liquid phases, wash the solid phase with deionized water to remove the residual acid solution, dry at 80 °C for 30 min. Soak the dried solid phase in the composite aqueous solution of nickel chloride and sodium iodide to form a suspension. The solid-liquid mass ratio of the solid phase soaked in the composite aqueous solution of nickel chloride and sodium iodide to form the suspension is solid phase: composite aqueous solution of nickel chloride and sodium iodide = 1:100. Keep the suspension in a water bath at a constant temperature of 90 ± 2 °C for 10 min, with condensation reflux during the insulation process. After the insulation is completed, separate the solid and liquid phases, wash the solid phase with deionized water 3 times, and then dry at 80 °C for 30 min to obtain activated copper powder;

[0049] (2) Prepare a mixed solution of catechol and diethylenetriamine. In the mixed solution of catechol and diethylenetriamine, the concentration of catechol is 7 g / L, and the concentration of diethylenetriamine is 22 g / L, and the solvent is water. Add the mixed solution of catechol and diethylenetriamine to a 1 M Tris-HCl buffer solution to form a mixed solution. The volume ratio of the mixed solution of catechol and diethylenetriamine added to the Tris-HCl buffer solution is mixed solution of catechol and diethylenetriamine: Tris-HCl buffer solution = 1:10. Adjust the pH of the mixed solution to 8.5 with concentrated hydrochloric acid (37 wt%), and then add the activated copper powder to the mixed solution. The mass ratio of the activated copper powder added to the mixed solution is activated copper powder: mixed solution = 1:50. After adding the materials, stir the mixed solution for 5 h, then separate the solid and liquid phases, wash the solid phase with deionized water 3 times, and dry at 80 °C for 30 min. Add the dried solid phase to a silver ammonia solution. In the silver ammonia solution, the molar concentration of silver is 0.08 mol / L, and the pH is 11. The solid-liquid mass ratio of the dried solid phase added to the silver ammonia solution is dried solid phase: silver ammonia solution = 1:100. After adding the materials, stir the solution, and then dropwise add a glucose solution to the solution under stirring. The concentration of glucose in the glucose solution is 20 g / L, and the solvent is water. The volume ratio of the glucose solution dropped to the silver ammonia solution is glucose solution: silver ammonia solution = 1:10. After the addition of the materials is completed, continue to stir the solution for 20 min, then separate the solid and liquid phases, wash the solid phase with deionized water 3 times, and dry at 80 °C for 30 min to obtain the modified copper powder of this comparative example;

[0050] (3) Mix the modified copper powder, nickel powder and silicon powder evenly by ball milling to obtain a mixed powder; the mass ratio of the modified copper powder, nickel powder and silicon powder is modified copper powder: nickel powder: silicon powder = 95:4:1; both the nickel powder and silicon powder are powders passing through a 1000-mesh sieve; the ball milling process parameters are: the ball-to-material mass ratio is ball: material = 1.5:1; the rotation speed is 120 r / min, and the ball milling time is 10 h; the mixed powder is hot-pressed and sintered into a shape in a hot-pressing furnace, and the hot-pressing sintering parameters are: the pressure is 30 MPa, the sintering temperature is 960 °C, and the sintering time is 1 h; then solution treatment is carried out at 900 °C for 2 h, and after solution treatment, it is water-cooled to room temperature, aged at 450 °C for 3 h, and after aging treatment, it is air-cooled to room temperature to obtain a Cu-Ni-Si composite material.

[0051] Comparative Example 3

[0052] A method for comparison, the steps include:

[0053] (1) Prepare a composite aqueous solution of nickel chloride and sodium iodide; in the composite aqueous solution of nickel chloride and sodium iodide, the concentration of nickel chloride is 19 g / L, the concentration of sodium iodide is 650 g / L, and the solvent is water; pass the copper powder through a 1000-mesh sieve, collect the sieved powder, soak the sieved powder in acetone for 10 min to remove oil, then carry out solid-liquid separation, dry the solid phase powder at 80 °C for 30 min, soak the dried powder in a dilute hydrochloric acid solution for 8 min to remove the oxide scale, and the mass percentage of the solute in the dilute hydrochloric acid is 5%; then carry out solid-liquid separation, wash the solid phase with deionized water to remove the residual acid solution, dry it at 80 °C for 30 min, soak the dried solid phase in the composite aqueous solution of nickel chloride and sodium iodide to form a suspension, and the solid-liquid mass ratio of the solid phase soaked in the composite aqueous solution of nickel chloride and sodium iodide to form a suspension is solid phase: composite aqueous solution of nickel chloride and sodium iodide = 1:100; keep the suspension in a water bath at a constant temperature of 90 ± 2 °C for 10 min, and carry out condensation reflux during the insulation process; after the insulation is completed, carry out solid-liquid separation, wash the solid phase with deionized water 3 times, and then dry it at 80 °C for 30 min to obtain activated copper powder;

[0054] (2) Prepare a mixed aqueous solution of palladium chloride, disodium ethylenediaminetetraacetate, sodium citrate, ammonium chloride, and glycine as the palladium plating solution. The concentrations of each component in the palladium plating solution are: palladium chloride 0.05 g / 100 mL; disodium ethylenediaminetetraacetate 1.1 g / 100 mL; sodium citrate 0.7 g / 100 mL; ammonium chloride 0.04 g / 100 mL; glycine 0.02 g / 100 mL; the solvent is water. Immerse the activated copper powder in the palladium plating solution to form a suspension. The solid-liquid ratio of the activated copper powder immersed in the palladium plating solution is activated copper powder:palladium plating solution = 1 g / 100 mL. Stir the suspension, add ammonia water to the suspension to adjust the pH to 8. The mass percentage of the solute in the ammonia water is 25%. Then keep the suspension at a constant temperature of 60 ± 2 °C in a water bath, add sodium hypophosphite. The mass ratio of the added sodium hypophosphite to the mass of the activated copper powder added to the palladium plating solution is sodium hypophosphite:activated copper powder = 0.3:1. After the feeding is completed, continue to keep the suspension at a constant temperature of 60 ± 2 °C in a water bath and stir for 60 min, then separate the solid and liquid. Wash the solid phase with deionized water 3 times, and then dry it at 80 °C for 30 min to obtain palladium-plated powder;

[0055] (3) Add the palladium-plated powder to the silver ammonia solution. In the silver ammonia solution, the molar concentration of silver is 0.08 mol / L and the pH is 11. The solid-liquid mass ratio of the palladium-plated powder added to the silver ammonia solution is palladium-plated powder:silver ammonia solution = 1:100. After feeding, stir the solution, and then dropwise add the glucose solution to the solution under stirring. The concentration of glucose in the glucose solution is 20 g / L and the solvent is water. The volume ratio of the added glucose solution to the volume of the silver ammonia solution is glucose solution:silver ammonia solution = 1:10. After the feeding is completed, continue to stir the solution for 20 min, then separate the solid and liquid. Wash the solid phase with deionized water 3 times and dry it at 80 °C for 30 min to obtain the modified copper powder of this comparative example;

[0056] (4) Ball-mill and mix the modified copper powder, nickel powder, and silicon powder evenly to obtain a mixed powder. The mass ratio of the modified copper powder, nickel powder, and silicon powder is modified copper powder:nickel powder:silicon powder = 95:4:1. Both the nickel powder and the silicon powder are powders passing through a 1000-mesh sieve. The ball-milling process parameters are: the ball-to-material mass ratio is ball:material = 1.5:1; the rotation speed is 120 r / min, and the ball-milling time is 10 h. The mixed powder is hot-pressed and sintered into shape in a hot-pressing furnace. The hot-pressing sintering parameters are: the pressure is 30 MPa, the sintering temperature is 960 °C, and the sintering time is 1 h. Then perform solution treatment at 900 °C for 2 h, cool it to room temperature in water after solution treatment, perform aging treatment at 450 °C for 3 h, and air-cool it to room temperature after aging treatment to obtain the Cu-Ni-Si composite material.

[0057] Example 5

[0058] The electrical conductivity of the Cu-Ni-Si composite materials prepared by the methods described in the above examples and comparative examples was measured using an eddy current conductivity meter. The data of 5 samples were tested in each group, and the average value was taken. In addition, the Vickers hardness of the Cu-Ni-Si composite materials prepared by the methods described in the above examples and comparative examples was measured using a micro Vickers hardness tester. The load was 294.3 N, and the pressure was maintained for 20 s. The data of 5 points were tested for each group of specimens, and the average value was taken. The results are shown in Table 1.

[0059] As can be seen from Table 1, the Cu-Ni-Si composite materials prepared by the method of the present invention can significantly improve the electrical conductivity and surface hardness of the Cu-Ni-Si materials. This may be because the modified copper powder is more likely to obtain fine grains during the sintering and aging processes, thus playing a certain role in refining the grains. At the same time, after the copper powder is modified, during the sintering, solution and aging processes of the material, it can promote the precipitation of nickel and silicon atoms in the crystal lattice at the grain boundaries, reduce the solid solution amount of silicon, reduce the scattering effect of silicon atoms on electrons, and promote the movement of free electrons, resulting in an increase in the overall electrical conductivity of the material. At the same time, the precipitated silicon nickel forms a second phase at the grain boundaries, hindering the movement of dislocations and forming a second phase strengthening effect.

[0060] Table 1

[0061]

[0062]

[0063] The above has introduced the technical solutions provided by the present invention in detail. For those of ordinary skill in the art, according to the idea of the embodiments of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A method for improving the electrical conductivity of a Cu-Ni-Si composite material, characterized in that the steps include: (1) preparing a composite aqueous solution of nickel chloride and sodium iodide; passing copper powder through a 1000-mesh sieve, collecting the sieved powder, soaking the sieved powder in acetone for more than 10 minutes, then performing solid-liquid separation, drying the solid phase powder at 80° C. for more than 30 minutes, soaking the dried powder in a dilute hydrochloric acid solution for more than 8 minutes, then performing solid-liquid separation, washing the solid phase with deionized water to remove residual acid, drying at 80° C. for more than 30 minutes, and soaking the dried solid phase in the composite aqueous solution of nickel chloride and sodium iodide to form a suspension; keeping the suspension in a water bath at a constant temperature of 90±2° C. for more than 10 minutes, and condensing and refluxing during the insulation process; after the insulation is completed, the solid-liquid separation is performed, the solid phase is washed with deionized water for more than 3 times, and then dried at 80° C. for more than 30 minutes to obtain activated copper powder; (2) preparing a mixed aqueous solution of palladium chloride, disodium ethylenediaminetetraacetate, sodium citrate, ammonium chloride, and glycine as a palladium plating solution; the concentrations of the components in the palladium plating solution are: palladium chloride 0.05-0.06 g / 100 mL; disodium ethylenediaminetetraacetate 1.0-1.2 g / 100 mL; sodium citrate 0.6-0.8 g / 100 mL; ammonium chloride 0.04-0.05 g / 100 mL; glycine 0.01-0.03 g / 100 mL; the solvent is water; immersing the activated copper powder in the palladium plating solution to form a suspension, wherein the activated copper powder is immersed in the palladium plating solution at a solid-liquid ratio of ::: Powder: palladium plating solution = 1g / 100mL, stir the suspension, add ammonia water to the suspension to adjust the pH to 8, the mass percentage of the solute in the ammonia water is 25%; then keep the suspension at 60±2°C in a water bath, add sodium hypophosphite, the mass ratio of the added sodium hypophosphite to the activated copper powder added to the palladium plating solution is sodium hypophosphite: activated copper powder = 0.3-0.4:1; after the addition is completed, continue to stir the suspension at 60±2°C in a water bath for 60-80min, then separate the solid and liquid, wash the solid phase with deionized water for more than 3 times, and then dry at 80°C for more than 30min to obtain palladium-plated powder; (3) preparing a mixed solution of catechol and diethylenetriamine, adding the mixed solution of catechol and diethylenetriamine to a 1M Tris-HCl buffer to form a mixed solution, adding concentrated hydrochloric acid to the mixed solution to adjust the pH to 8.5, and then adding the palladium-plated powder to the mixed solution, stirring the mixed solution for 5 to 6 hours after adding the materials, and then separating the solid and liquid, washing the solid phase with deionized water for more than 3 times, drying at 80° C. for more than 30 minutes, adding the dried solid phase to a silver ammonia solution, stirring the solution after adding the materials, and then dropping a glucose solution into the solution under stirring, continuing to stir the solution for more than 20 minutes after the addition is completed, and then separating the solid and liquid, washing the solid phase with deionized water for more than 3 times, and drying at 80° C. for more than 30 minutes to obtain a modified copper powder; (4) The modified copper powder, nickel powder and silicon powder are ball-milled and mixed to obtain a mixed powder; the mixed powder is hot-pressed and sintered in a hot press furnace, and then solution-treated at 900°C for 2 hours, water-cooled to room temperature after solution-treatment, aged at 450°C for 3 to 4 hours, and air-cooled to room temperature after aging treatment to obtain a Cu-Ni-Si composite material.

2. A method for improving the electrical conductivity of a Cu-Ni-Si composite material according to claim 1, characterized in that: In the step (1), in the composite aqueous solution of nickel chloride and sodium iodide, the concentration of nickel chloride is 18-20 g / L, the concentration of sodium iodide is 600-700 g / L, and the solvent is water; the solid phase is immersed in the composite aqueous solution of nickel chloride and sodium iodide to form a suspension, and the solid-liquid mass ratio of the solid phase: composite aqueous solution of nickel chloride and sodium iodide is 1:

100.

3. A method for improving the electrical conductivity of a Cu-Ni-Si composite material according to claim 1, characterized in that: In the step (3), in the mixed solution of catechol and diethylenetriamine, the concentration of catechol is 6-8 g / L, the concentration of diethylenetriamine is 20-24 g / L, and the solvent is water; the volume ratio of the mixed solution of catechol and diethylenetriamine to Tris-HCl buffer is 1:10; the mass ratio of the palladium-plated powder added to the mixed solution is 1:

50.

4. A method for improving the electrical conductivity of a Cu-Ni-Si composite material according to claim 1, characterized in that: In the step (3), the molar concentration of silver in the silver ammonia solution is 0.08-0.09 mol / L, and the pH is 11; the solid-liquid mass ratio of the dried solid phase added to the silver ammonia solution is the dried solid phase: silver ammonia solution = 1:100; the concentration of glucose in the glucose solution is 20 g / L, and the solvent is water; The volume ratio of the glucose solution added dropwise to the silver ammonia solution is glucose solution:silver ammonia solution=1:

10.

5. A method for preparing a Cu-Ni-Si composite material for improving electrical conductivity according to claim 1, characterized in that: In the step (4), the mass ratio of modified copper powder, nickel powder and silicon powder is modified copper powder: nickel powder: silicon powder = 95:4:1; and the nickel powder and silicon powder are both powders that pass through a 1000-mesh sieve.

6. A method for preparing a Cu-Ni-Si composite material for improving electrical conductivity according to claim 1, characterized in that: In the step (4), the ball milling process parameters are: ball to material mass ratio is ball: material = 1.5:1; the rotation speed is 120r / min, and the ball milling time is 10h; the hot pressing sintering parameters are: pressure is 30MPa, sintering temperature is 960°C, and sintering time is 1h.

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