Copper alloy wire and preparation method thereof

Abstract

The invention discloses a copper alloy wire and a preparation method thereof.The preparation method comprises the steps that a molybdenum metal or tungsten metal bar is subjected to repeated heating and heat preservation treatment and rotary swaging till a rotary swaged bar with the diameter being 6.5-8 mm is obtained; the rotary swaging bar is subjected to first annealing treatment, and then repeated cold drawing and second annealing treatment are conducted till a drawn wire with the diameter being 2-5 mm is obtained; and the drawn wire is subjected to copper plating and copper infiltration treatment, and the tungsten-copper or molybdenum-copper alloy wire is obtained. The density of the alloy wire can be improved, the thermal conductivity and the electrical conductivity of the alloy wire can be improved, meanwhile, the utilization rate of raw materials can be increased, the production cost is reduced, and the obtained material meets the use requirements of different high-voltage switches and trigger electrodes.

Description

Technical Field

[0001] The invention relates to the technical field of a method for processing a copper alloy wire, in particular to the technical field of a method for processing a tungsten-copper or molybdenum-copper wire. Background Art

[0002] Tungsten copper and molybdenum copper alloys have the characteristics of high strength, arc erosion resistance, low expansion coefficient, high electrical conductivity and thermal conductivity, so they are widely used in the fields of electrical contacts, electrodes, electronic packaging and heat sink materials of high-voltage electrical switches. Among them, when tungsten copper and molybdenum copper alloys are used for high-voltage switches and trigger electrodes, the requirements on specifications and performance are more stringent. For example, the diameter of the alloy usually needs to be around 3 mm, which is a thinner wire material to ensure a close fit with the switch structure and uniform current transmission. The alloy needs to have high thermal conductivity and electrical conductivity to ensure rapid current transmission and effective heat dissipation to avoid local overheating and cause failures. It also needs to have high density and low gas content to reduce defects, ensure high mechanical strength, reduce the formation of bubbles, and improve arc resistance and thermal stability.

[0003] In the prior art, there are two main methods for preparing tungsten copper and molybdenum copper alloy wires: one is to gradually reduce tungsten copper or molybdenum copper rods that are several times larger than the target size to the required size through mechanical processing, which is the reduction method; the other is to perform multi-stage stretching and forging on a rotary forging machine to gradually refine and elongate the tungsten copper or molybdenum copper rods to the required size, which is the rotary forging method. Of the above two methods, the reduction method usually requires the use of sintered tungsten copper or molybdenum copper rods. The rods themselves have pore defects that are difficult to eliminate and will reduce the material's density, electrical and thermal conductivity, and mechanical strength. Reduction will also cause a large amount of waste of raw materials and increase production costs. The rotary forging method is prone to cause material fracture, splitting, and other phenomena when processing hard and brittle tungsten copper or molybdenum copper alloys, which is difficult to process and has a low yield. Summary of the invention

[0004] In view of the defects of the prior art, the purpose of the present invention is to propose a new copper alloy wire and a preparation method thereof. The preparation method can obtain tungsten-copper and molybdenum-copper alloy wires with adjustable composition ratios by regulating the gap between the tungsten wire and the molybdenum wire and the thickness of the electroplated copper layer. The preparation method can improve the density of the alloy wire and increase its thermal conductivity and electrical conductivity. At the same time, it can improve the utilization rate of raw materials and reduce production costs, so that the obtained materials meet the use requirements of different high-voltage switches and trigger electrodes.

[0005] The technical solution of the present invention is as follows: A method for preparing a copper alloy wire, comprising: The raw metal rod is heated and heat-insulated, and then forged at a forging rate of 1.2-1.6 m / min, and the above heating and heat-insulating treatment and forging process are repeated until a forged rod with a diameter of 6.5-8 mm is obtained; Performing a first annealing treatment on the rotary forging rod in a hydrogen atmosphere to obtain an annealed rod; The annealed rod is cold drawn at a drawing rate of 5 to 8 m / min, and then a second annealing treatment is performed in a hydrogen atmosphere, and the above cold drawing and second annealing treatment processes are repeated until a drawn wire with a diameter of 2 to 5 mm is obtained; The drawn wire is cut, degreased and activated, and then copper plated to obtain a copper plated wire; In a hydrogen atmosphere, the copper-plated wire is subjected to copper infiltration treatment by a melt infiltration method to obtain a copper alloy wire with a diameter of 2 to 5 mm; Wherein, the raw material metal is selected from tungsten metal and / or molybdenum metal; the temperature of the first annealing treatment is 800~900℃, and the time is 20~40min; the temperature of the second annealing treatment is 500~600℃, and the time is 10~30min, and the time gradually decreases as the diameter of the annealed rod after drawing decreases.

[0006] The above technical scheme of the present invention realizes the regulation of the internal gap of the raw metal wires, namely tungsten wire and molybdenum wire, by heating and heat preservation treatment and controlling process parameters such as rotary forging speed, drawing speed, annealing temperature and time, so that the raw metal has strong toughness and excellent processing performance during rotary forging and drawing, and no material fracture or splitting occurs. When combined with the dissolution and infiltration process and its parameters of the present technology, the structure of the obtained copper alloy wire is dense and uniform, and the comprehensive performance, diameter control accuracy and yield rate of the copper alloy wire are significantly improved.

[0007] According to some preferred embodiments of the present invention, the temperature of the heating and heat preservation treatment is 800-1000° C., and the time is 10-30 min.

[0008] According to some preferred embodiments of the present invention, during the cold drawing, graphite emulsion is coated on the surface of the annealed rod as a lubricant.

[0009] According to some preferred embodiments of the present invention, the cutting is to cut the drawn wire into 300 mm in length.

[0010] According to some preferred embodiments of the present invention, the copper infiltration treatment is carried out at a temperature of 1300-1400° C. for 2-3 hours.

[0011] According to some preferred embodiments of the present invention, obtaining the raw metal rod comprises: The raw metal powder is pressed into a rod-shaped blank by isostatic pressing; The rod-shaped blank is sintered in a hydrogen atmosphere to obtain a rod of the raw metal, wherein the sintering temperature is 1300-1500° C. and the sintering holding time is 1.5-3.5 hours.

[0012] According to some preferred embodiments of the present invention, the isostatic pressing pressure is 160-200 MPa.

[0013] According to some preferred embodiments of the present invention, in the copper alloy wire, the mass content of the raw material metal is 50-90% of the total mass of the copper alloy wire.

[0014] According to some preferred embodiments of the present invention, the thickness of the copper layer obtained by the copper plating process is 0.09-0.4 mm.

[0015] The present invention has the following beneficial effects: The preparation method of the present invention can effectively improve the utilization rate of raw materials and reduce production costs. The prepared tungsten-copper or molybdenum-copper alloy wire has high density, the composition and ratio can be flexibly adjusted, the material diameter can be accurately controlled, and the thermal and mechanical properties of the material are excellent. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a schematic diagram of the preparation process of the tungsten-copper or molybdenum-copper alloy wire in the present invention. DETAILED DESCRIPTION

[0017] The technical scheme of the present invention will be further described below in conjunction with the embodiments and drawings of the present invention. The embodiments described below are only 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 creative work should fall within the scope of protection of the present invention.

[0018] Example 1 Refer to the attached Figure 1 , prepare tungsten copper alloy wire by the following steps: (1) 197 g of tungsten powder with a particle size of 5 µm was loaded into a rubber sleeve with a diameter of 12.5 mm and pressed into a rod blank using an isostatic press at 180 MPa; (2) Place the rod blank in a continuous sintering furnace in a hydrogen atmosphere, control the temperature to 1400°C, and keep it for 2.5 hours to obtain a tungsten rod with a diameter of 10 mm; (3) The tungsten rod was heated to 900 °C in a heating furnace and kept warm for 20 min, and then sent to a rotary forging machine for rotary forging to a diameter of 8 mm at a rotary forging speed of 1.2-1.6 m / min. The heating and rotary forging processes were repeated until a rod with a diameter of 6.5 mm was obtained. (4) The obtained rod is annealed in a hydrogen atmosphere at a temperature of 800°C for 30 min. The annealed rod is cold drawn. During the drawing, graphite emulsion is coated on the surface of the rod as a lubricant. The drawing rate is 5-8 m / min. The rod passes through dies with diameters of 6 mm and 5.5 mm in turn. The rod is then annealed at 500°C for 10-20 min under the protection of a hydrogen atmosphere. The annealing time decreases as the diameter decreases. The above drawing and annealing treatments are repeated until the tungsten rod is drawn into a wire of 2-5 mm. The wire is cut into 300 mm lengths. (5) Degreasing and activating the tungsten wire obtained in step (4), and then placing it in an electroplating device, and plating a copper layer with a thickness of 0.16-0.40 mm by adjusting the concentration of the electroplating solution and the electroplating time, to obtain a copper-plated tungsten wire; wherein the activation process is: mixing 30-50 mL / L of nitric acid and 30-50 mL / L of sulfuric acid in water to prepare an activation solution, and then immersing the entire tungsten wire in the activation solution, using ultrasound to fully stir, the activation process lasts for 2-5 s, after the activation is completed, taking out the tungsten wire, and rinsing the surface of the tungsten wire with clean water to remove the residual activation solution; (6) Placing the copper-plated tungsten wire in a hydrogen atmosphere infiltration furnace for copper infiltration at a temperature of 1300°C for a holding time of 2 h to obtain a tungsten-copper alloy wire with a diameter of 2 to 5 mm; The tungsten-copper alloy wire prepared in this embodiment has a diameter of 2-5 mm, a length of 300 mm, a tungsten content of 80 wt %, and a copper content of 20 wt %.

[0019] Example 2 Refer to the attached Figure 1 , prepare tungsten copper alloy wire by the following steps: (1) 245 g of tungsten powder with a particle size of 5 µm was loaded into a rubber sleeve with a diameter of 12.5 mm and pressed into a rod blank using an isostatic press at 200 MPa; (2) Place the rod blank in a continuous sintering furnace in a hydrogen atmosphere, control the temperature to 1400°C, and keep it for 2.5 hours to obtain a tungsten rod with a diameter of 10 mm; (3) The tungsten rod was heated to 900 °C in a heating furnace and kept warm for 20 min, and then sent to a rotary forging machine for rotary forging to a diameter of 8 mm at a rotary forging speed of 1.2-1.6 m / min. The heating and rotary forging processes were repeated until a rod with a diameter of 6.5 mm was obtained. (4) The obtained rod is annealed in a hydrogen atmosphere at a temperature of 800°C for 30 min. The annealed rod is cold drawn. During the drawing, graphite emulsion is coated on the surface of the rod as a lubricant. The drawing rate is 5-8 m / min. The rod passes through dies with diameters of 6 mm and 5.5 mm in turn. The rod is then annealed at 500°C for 10-20 min under the protection of a hydrogen atmosphere. The annealing time decreases as the diameter decreases. The above drawing and annealing treatments are repeated until the tungsten rod is drawn into a wire of 2-5 mm. The wire is cut into 300 mm lengths. (5) Degreasing and activating the tungsten wire obtained in step (4), and then placing it in an electroplating device, and plating a copper layer with a thickness of 0.09-0.23 mm by adjusting the concentration of the electroplating solution and the electroplating time, so as to obtain a copper-plated tungsten wire; wherein the activation process is as follows: 30-50 mL / L of nitric acid and 30-50 mL / L of sulfuric acid are mixed in water to prepare an activation solution, and then the tungsten wire is completely immersed in the activation solution, and ultrasonic waves are used for sufficient stirring. The activation process lasts for 2-5 seconds. After the activation is completed, the tungsten wire is taken out and the surface of the tungsten wire is rinsed with clean water to remove the residual activation solution.

[0020] (6) Placing the copper-plated tungsten wire in a hydrogen atmosphere infiltration furnace for copper infiltration at a temperature of 1300°C for a holding time of 2 h to obtain a tungsten-copper alloy wire with a diameter of 2 to 5 mm; The tungsten-copper alloy wire prepared in this embodiment has a diameter of 2-5 mm, a length of 300 mm, a tungsten content of 90 wt %, and a copper content of 10 wt %.

[0021] Example 3 Refer to the attached Figure 1 , the molybdenum-copper alloy wire is prepared by the following steps: (1) 155 g of molybdenum powder with a particle size of 5 µm was loaded into a rubber sleeve with a diameter of 15 mm and pressed into a rod blank using an isostatic press at 160 MPa; (2) Placing the rod blank in a continuous sintering furnace in a hydrogen atmosphere, controlling the temperature to 1400°C, and keeping the temperature for 2.5 hours to obtain a molybdenum rod with a diameter of 12 mm; (3) The molybdenum rod was heated to 900 °C in a heating furnace and kept at this temperature for 20 min, and then sent to a rotary forging machine for rotary forging to a diameter of 10 mm at a rotary forging speed of 1.2-1.6 m / min. The heating and rotary forging processes were repeated until a rod with a diameter of 8 mm was obtained. (4) The obtained rod is annealed in a hydrogen atmosphere at a temperature of 900°C for 30 min. The annealed rod is cold drawn. During the drawing, graphite emulsion is coated on the surface of the rod as a lubricant. The drawing rate is 5-8 m / min. The rod passes through dies with diameters of 7.5 mm and 7 mm in turn. Then, the rod is annealed at 600°C for 10-20 min under the protection of a hydrogen atmosphere. The annealing time decreases as the diameter decreases. The above drawing and annealing treatments are repeated until the molybdenum rod is drawn into a wire of 2-5 mm. The wire is cut into 300 mm lengths. (5) Degreasing and activating the molybdenum wire obtained in step (4), and then placing it in an electroplating device, and plating a copper layer with a thickness of 0.15-0.38 mm by adjusting the concentration of the electroplating solution and the electroplating time, to obtain a copper-plated molybdenum wire; wherein the activation process is: mixing 30-50 mL / L of nitric acid and 30-50 mL / L of sulfuric acid in water to prepare an activation solution, and then immersing the entire molybdenum wire in the activation solution, using ultrasound to fully stir, the activation process lasts for 2-5 s, after the activation is completed, taking out the molybdenum wire, and rinsing the surface of the molybdenum wire with clean water to remove the residual activation solution; (6) Placing the copper-plated molybdenum wire in a hydrogen atmosphere infiltration furnace for copper infiltration at a temperature of 1300°C for a holding time of 2 h to obtain a molybdenum-copper alloy wire with a diameter of 2 to 5 mm; The molybdenum-copper alloy wire prepared in this embodiment has a diameter of 2-5 mm, a length of 300 mm, a molybdenum content of 70 wt %, and a copper content of 30 wt %.

[0022] Example 4 Refer to the attached Figure 1 , the molybdenum-copper alloy wire is prepared by the following steps: (1) 180 g of molybdenum powder with a particle size of 5 µm was loaded into a rubber sleeve with a diameter of 15 mm and pressed into a rod blank using an isostatic press at 180 MPa; (2) Placing the rod blank in a continuous sintering furnace in a hydrogen atmosphere, controlling the temperature to 1400°C, and keeping the temperature for 2.5 hours to obtain a molybdenum rod with a diameter of 12 mm; (3) The molybdenum rod was heated to 900 °C in a heating furnace and kept at this temperature for 20 min, and then sent to a rotary forging machine for rotary forging to a diameter of 10 mm at a rotary forging speed of 1.2-1.6 m / min. The heating and rotary forging processes were repeated until a rod with a diameter of 8 mm was obtained. (4) The obtained rod is annealed in a hydrogen atmosphere at a temperature of 900°C for 30 min. The annealed rod is cold drawn. During the drawing, graphite emulsion is coated on the surface of the rod as a lubricant. The drawing rate is 5-8 m / min. The rod passes through dies with diameters of 7.5 mm and 7 mm in turn. Then, the rod is annealed at 600°C for 10-20 min under the protection of a hydrogen atmosphere. The annealing time decreases as the diameter decreases. The above drawing and annealing treatments are repeated until the molybdenum rod is drawn into a wire of 2-5 mm. The wire is cut into 300 mm lengths. (5) Degreasing and activating the molybdenum wire obtained in step (4), and then placing it in an electroplating device, and plating a copper layer with a thickness of 0.11-0.26 mm by adjusting the concentration of the electroplating solution and the electroplating time, to obtain a copper-plated molybdenum wire; wherein the activation process is: mixing 30-50 mL / L of nitric acid and 30-50 mL / L of sulfuric acid in water to prepare an activation solution, and then immersing the entire molybdenum wire in the activation solution, using ultrasound to fully stir, the activation process lasts for 2-5 s, after the activation is completed, taking out the molybdenum wire, and rinsing the surface of the molybdenum wire with clean water to remove the residual activation solution; (6) Placing the copper-plated molybdenum wire in a hydrogen atmosphere infiltration furnace for copper infiltration at a temperature of 1300°C for a holding time of 2 h to obtain a molybdenum-copper alloy wire with a diameter of 2 to 5 mm; The molybdenum-copper alloy wire prepared in this embodiment has a diameter of 2-5 mm, a length of 300 mm, a molybdenum content of 80 wt %, and a copper content of 20 wt %.

[0023] It should be noted that the above is only a preferred embodiment of the present invention, which should not limit the protection scope of the technical solution of the present invention. Any modification of the technical solution recorded in the above embodiments and equivalent replacement of technical features by ordinary technicians in the field within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a copper alloy wire, characterized in that: It includes: The raw metal rod is heated and heat-insulated, and then forged at a forging rate of 1.2-1.6 m / min, and the above heating and heat-insulating treatment and forging process are repeated until a forged rod with a diameter of 6.5-8 mm is obtained; Performing a first annealing treatment on the rotary forging rod in a hydrogen atmosphere to obtain an annealed rod; The annealed rod is cold drawn at a drawing rate of 5 to 8 m / min, and then a second annealing treatment is performed in a hydrogen atmosphere, and the above cold drawing and second annealing treatment processes are repeated until a drawn wire with a diameter of 2 to 5 mm is obtained; The drawn wire is cut, degreased and activated, and then copper plated to obtain a copper plated wire; In a hydrogen atmosphere, the copper-plated wire is subjected to copper infiltration treatment by a melt infiltration method to obtain a copper alloy wire with a diameter of 2 to 5 mm; Wherein, the raw material metal is selected from tungsten metal and / or molybdenum metal; the temperature of the first annealing treatment is 800-900°C, and the time is 20-40 minutes; the temperature of the second annealing treatment is 500-600°C, and the time is 10-30 minutes, and it gradually decreases as the diameter of the annealed rod after drawing decreases.

2. The preparation method according to claim 1, characterized in that: The temperature of the heating and heat preservation treatment is 800-1000° C. and the time is 10-30 minutes.

3. The preparation method according to claim 1, characterized in that: When the cold drawing is performed, graphite emulsion is coated on the surface of the annealed rod as a lubricant.

4. The preparation method according to claim 1, characterized in that: The cutting is to cut the drawn wire into 300 mm length.

5. The preparation method according to claim 1, characterized in that: The copper infiltration treatment is carried out at a temperature of 1300-1400° C. and for a time of 2-3 hours.

6. The preparation method according to claim 1, characterized in that: The obtaining of the raw metal bars includes: The raw metal powder is pressed into a rod-shaped blank by isostatic pressing; The rod-shaped blank is sintered in a hydrogen atmosphere to obtain a rod of the raw metal, wherein the sintering temperature is 1300-1500° C. and the sintering holding time is 1.5-3.5 hours.

7. The preparation method according to claim 6, characterized in that: The isostatic pressing pressure is 160-200 MPa.

8. The preparation method according to claim 1, characterized in that: In the copper alloy wire, the mass content of the raw metal is 50-90% of the total mass of the copper alloy wire.

9. The preparation method according to claim 1, characterized in that: The copper layer thickness obtained by the copper plating process is 0.09-0.4 mm.

10. The copper alloy wire prepared by the preparation method according to any one of claims 1 to 9.

Images