Silver-nickel contact material with high large current impact resistance and preparation method of silver-nickel contact material

Abstract

The invention relates to the field of electrical contact materials, and particularly discloses a silver-nickel contact material with high large current impact resistance and a preparation method thereof. The preparation method of the silver-nickel contact material comprises the following steps that S1, silver and a first additive are mixed, powder is prepared through smelting and atomization, then the powder is dried and sieved, and silver alloy powder is obtained; s2, silver alloy powder, nickel powder and second additive powder are evenly mixed, mixed powder is obtained, then an ingot blank is prepared through cold isostatic pressing, and then the ingot blank is sintered in the hydrogen atmosphere; and S3, performing hot extrusion on the sintered ingot blank to prepare a wire material, and then drawing to obtain the silver-nickel contact material. According to the silver-nickel contact material and the preparation method thereof, the adding form of the first additive and the second additive is combined with the smelting, atomizing, powder preparing and powder mixing process for application, the silver-nickel contact material with high strength, high large-current impact resistance and high fusion welding performance is prepared, and the use requirements of medium-and-small-capacity electric appliances under the impact of large surge current can be met.

Description

Technical Field

[0001] This application relates to the field of electrical contact materials, and more specifically, to a silver-nickel contact material with high resistance to high current surges and its preparation method. Background Technology

[0002] Silver-nickel materials are widely used as electrical contact materials in small and medium-capacity control electrical appliances due to their excellent electrical conductivity, thermal conductivity, resistance to arc erosion, and good plasticity. As control electrical appliances become increasingly lightweight and miniaturized, more stringent requirements are being placed on the overall electrical performance of electrical contact materials. These materials not only require high switching capability and low, stable contact resistance, but also a certain level of strength and anti-adhesion properties.

[0003] Currently, the most common method for preparing silver-nickel contact materials is powder metallurgy. This involves mixing silver powder, nickel powder, and additive powders in a specific ratio using a mixing device, then loading the mixture into a rubber mold and pressing it into a powder ingot using isostatic pressing or mechanical pressing. The ingot is then sintered at high temperature to densify the particles. After sintering, the ingot is heated and extruded into wires or strips, which are then processed into the required dimensions through multiple drawing or rolling processes. Finally, stress is relieved by annealing or repeated pressing-sintering cycles are performed to optimize performance. However, silver-nickel contact materials prepared by this method are only suitable for small to medium capacity electrical appliances under resistive loads. Under the impact of large surge currents, they are prone to rapid burn-out or welding, leading to electrical failure.

[0004] Therefore, it is of great significance to study a silver-nickel contact material with high strength, high resistance to high current impact and high weldability. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a silver-nickel contact material with high resistance to high current surges and its preparation method. This silver-nickel contact material is particularly suitable for environments with large surge current surges.

[0006] Firstly, this application provides a method for preparing a silver-nickel contact material with high resistance to high-current impact, which adopts the following technical solution: A method for preparing a silver-nickel contact material with high resistance to high current surges includes the following steps: S1. Silver and the first additive are mixed, smelted, atomized, and powdered, then dried and sieved to obtain silver alloy powder; the first additive includes one or more of nickel, copper, lanthanum, cerium, and yttrium; S2. The silver alloy powder, nickel powder and the second additive powder are mixed evenly to obtain a mixed powder, which is then cold isostatically pressed into an ingot, and then sintered in a hydrogen atmosphere; the second additive powder includes silver tungstate powder and / or silver molybdate powder. S3. The sintered ingot is hot-extruded into wire and then drawn to obtain silver-nickel contact material.

[0007] Preferably, in step S1, the amount of the first additive is 0.1-0.8% of the total mass of silver and the first additive.

[0008] Preferably, in step S2, by mass percentage, the mixed powder contains 8-40% nickel powder, 1-2% second additive powder, and the remainder is silver alloy powder.

[0009] Preferably, the nickel powder has a Fisher particle size of 2-8 μm, and the second additive powder has a particle size of 1-5 μm.

[0010] Preferably, the specific sintering conditions in S2 are: sintering at a temperature of 200-920℃ for 10-16 hours.

[0011] Preferably, the heating temperature of hot extrusion in S3 is 800-920℃.

[0012] Secondly, this application provides a silver-nickel contact material with high resistance to high current surges, prepared by the above-mentioned method for preparing silver-nickel contact materials with high resistance to high current surges.

[0013] In summary, this application has the following beneficial technical effects: This application combines the addition of the first and second additives with smelting, atomization, powder preparation, and mixing processes to produce a silver-nickel contact material with high strength, high resistance to high-current surges, and high weldability, meeting the requirements of small and medium-capacity electrical appliances under the impact of large surge currents. Specifically, this application places silver and the first additive in a medium-frequency smelting furnace, using a medium-frequency power supply to generate an alternating magnetic field, causing eddy currents to form inside the metal raw material and melting it. The first additive is then added to the molten silver to form a silver alloy. Then, a gas atomization method is used, using high-pressure inert gas to impact the molten silver alloy flow, atomizing it into micron-sized droplets. After drying, the droplets are sieved to obtain silver alloy powder. The silver alloy powder, nickel powder, and second additive powder are then mixed evenly before subsequent processes. Compared to directly mixing silver powder, nickel powder, and additive powder through physical mixing, this method significantly improves the uniformity of the material composition, resulting in superior material performance.

[0014] Furthermore, adding the first additive, in the form of silver alloy powder, to the silver-nickel contact material can strengthen the silver matrix, thereby improving the material's strength, oxidation resistance, arc burn resistance, and weld resistance. Simultaneously, adding the high-melting-point second additive, in the form of compound powder, to the silver-nickel contact material can improve the interfacial wettability between materials, not only enhancing the material's sinterability and ensuring its processing plasticity, but also further improving its anti-spatter ability, arc burn resistance, high-current impact resistance, and weld resistance. Detailed Implementation

[0015] All raw materials used in this application are commercially available products.

[0016] In the specific embodiments of this application, the silver in step S1 is a high-purity electrolytic silver ingot with a purity ≥99.99% and an oxygen content <50ppm.

[0017] In a specific embodiment of this application, the first additive in step S1 can be any one of nickel, copper, lanthanum, cerium and yttrium, or a combination of nickel, copper, lanthanum, cerium and yttrium in any proportion.

[0018] In specific embodiments of this application, nickel is in high-purity form, with a size of 5-10 mm and a purity > 99.9%. In specific embodiments of this application, copper is high-purity electrolytic copper ingot with a purity ≥ 99.9%. In specific embodiments of this application, lanthanum is high-purity electrolytic lanthanum ingot with a purity ≥ 99.9%. In specific embodiments of this application, cerium is high-purity electrolytic cerium ingot with a purity ≥ 99.9%. In specific embodiments of this application, yttrium is high-purity electrolytic yttrium ingot with a purity > 99.99%.

[0019] In the specific embodiments of this application, the melting temperature in step S1 is 100-150°C higher than the melting point of the metal raw material to avoid component segregation, and the melting is carried out in the presence of argon. The atomization method is gas atomization, which uses high-pressure inert gas (argon / nitrogen, pressure 3-7MPa) to impact the molten metal flow to form micron-sized droplets (particle size 1-150μm). After drying and passing through a 300-mesh sieve, the resulting silver alloy powder has high sphericity (>90%) and low oxygen content (<200ppm).

[0020] In a specific embodiment of this application, the Fisher particle size of the nickel powder in step S2 is 2-8 μm.

[0021] In a specific embodiment of this application, the second additive powder in step S2 can be silver tungstate powder, silver molybdate powder, or a mixture of silver tungstate powder and silver molybdate powder in any proportion.

[0022] In a specific embodiment of this application, the particle size of the second additive powder in step S2 is 1-5 μm.

[0023] In the specific embodiments of this application, the pressure of cold isostatic pressing in step S2 is 120-220MPa, the holding time is 60-120s, and the diameter φ of the isostatic pressing sleeve is 105-120mm.

[0024] In a specific embodiment of this application, the sintering conditions in step S2 are as follows: sintering at a temperature of 200-920°C for 10-16 hours.

[0025] In a preferred embodiment of this application, the specific sintering conditions in step S2 are as follows: heat to 200°C, hold for 2 hours, then heat to 400°C, hold for 2 hours, then heat to 600°C, hold for 2 hours, then heat to 800°C, hold for 2 hours, and finally heat to 920°C, hold for 4 hours.

[0026] In a specific embodiment of this application, the heating temperature of hot extrusion in step S3 is 800-920°C.

[0027] The applicant further elaborates on this application using the following examples.

[0028] Example 1 A method for preparing a silver-nickel contact material with high resistance to high current surges includes the following steps: S1. Mix 99.9 kg of high-purity electrolytic silver ingot and 0.1 kg of high-purity electrolytic lanthanum ingot, and then smelt, atomize and pulverize them. After drying, pass the mixture through a 300-mesh sieve to obtain silver alloy powder. S2. Mix 90 kg of silver alloy powder, 8 kg of nickel powder with a Fisher particle size of 2.7 μm and 2 kg of silver tungstate powder with a particle size of 1.8 μm evenly to obtain a mixed powder. Then, press it under a pressure of 120 MPa for 120 s to form an ingot. After that, sinter it in a hydrogen atmosphere. The specific sintering process is as follows: first, heat up to 200℃ and hold for 2 h; then heat up to 400℃ and hold for 2 h; then heat up to 600℃ and hold for 2 h; then heat up to 800℃ and hold for 2 h; finally, heat up to 920℃ and hold for 4 h. S3. The sintered ingot is heated to 800°C under hydrogen protection and hot-extruded into wire using a forward extrusion press. Then it is drawn to the required specifications to obtain silver-nickel contact material.

[0029] Example 2 A method for preparing a silver-nickel contact material with high resistance to high current surges includes the following steps: S1. Mix 99.2 kg of high-purity electrolytic silver ingots, 0.3 kg of high-purity nickel granules and 0.5 kg of high-purity electrolytic copper ingots, and then smelt, atomize and pulverize them. After drying, pass them through a 300-mesh sieve to obtain silver alloy powder. S2. Mix 59 kg of silver alloy powder, 40 kg of nickel powder with a Fisher particle size of 6 μm and 1 kg of silver molybdate powder with a particle size of 4.5 μm evenly to obtain a mixed powder. Then, pressurize it at 220 MPa for 60 s to form an ingot. Then, sinter it in a hydrogen atmosphere. The specific sintering process is as follows: first, heat up to 200℃ and hold for 2 h; then heat up to 400℃ and hold for 2 h; then heat up to 600℃ and hold for 2 h; then heat up to 800℃ and hold for 2 h; finally, heat up to 920℃ and hold for 4 h. S3. The sintered ingot is heated to 920°C under hydrogen protection and hot-extruded into wire using a forward extrusion press. Then it is drawn to the required specifications to obtain silver-nickel contact material.

[0030] Example 3 A method for preparing a silver-nickel contact material with high resistance to high current surges includes the following steps: S1. Mix 99.55 kg of high-purity electrolytic silver ingot, 0.15 kg of high-purity electrolytic cerium ingot and 0.3 kg of high-purity electrolytic copper ingot, and then smelt, atomize and pulverize them. After drying, pass them through a 300-mesh sieve to obtain silver alloy powder. S2. Mix 83.5 kg of silver alloy powder, 15 kg of nickel powder with a Fisher particle size of 4 μm and 1.5 kg of silver tungstate powder with a particle size of 3 μm evenly to obtain a mixed powder. Then, pressurize it at 170 MPa for 90 s to form an ingot. Then, sinter it in a hydrogen atmosphere. The specific sintering process is as follows: first, heat up to 200℃ and hold for 2 h; then heat up to 400℃ and hold for 2 h; then heat up to 600℃ and hold for 2 h; then heat up to 800℃ and hold for 2 h; finally, heat up to 920℃ and hold for 4 h. S3. The sintered ingot is heated to 860°C under hydrogen protection and hot-extruded into wire using a forward extrusion press. Then it is drawn to the required specifications to obtain silver-nickel contact material.

[0031] Example 4 A method for preparing a silver-nickel contact material with high resistance to high current surges includes the following steps: S1. Mix 99.75 kg of high-purity electrolytic silver ingot, 0.1 kg of high-purity nickel granules, 0.1 kg of high-purity electrolytic copper ingot and 0.05 kg of high-purity electrolytic yttrium ingot, and then smelt, atomize and pulverize the mixture. After drying, the mixture is passed through a 300-mesh sieve to obtain silver alloy powder. S2. Mix 83.5 kg of silver alloy powder, 15 kg of nickel powder with a Fisher particle size of 4 μm and 1.5 kg of silver tungstate powder with a particle size of 3 μm evenly to obtain a mixed powder. Then, pressurize it at 170 MPa for 90 s to form an ingot. Then, sinter it in a hydrogen atmosphere. The specific sintering process is as follows: first, heat up to 200℃ and hold for 2 h; then heat up to 400℃ and hold for 2 h; then heat up to 600℃ and hold for 2 h; then heat up to 800℃ and hold for 2 h; finally, heat up to 920℃ and hold for 4 h. S3. The sintered ingot is heated to 860°C under hydrogen protection and hot-extruded into wire using a forward extrusion press. Then it is drawn to the required specifications to obtain silver-nickel contact material.

[0032] Example 5 A method for preparing a silver-nickel contact material with high resistance to high current surges includes the following steps: S1. Mix 99.35 kg of high-purity electrolytic silver ingot, 0.15 kg of high-purity electrolytic cerium ingot, 0.3 kg of high-purity electrolytic copper ingot and 0.2 kg of high-purity nickel granules, and then smelt, atomize and pulverize them. After drying, pass them through a 300-mesh sieve to obtain silver alloy powder. S2. Mix 83.5 kg of silver alloy powder, 15 kg of nickel powder with a Fisher particle size of 4 μm and 1.5 kg of silver tungstate powder with a particle size of 3 μm evenly to obtain a mixed powder. Then, pressurize it at 170 MPa for 90 s to form an ingot. Then, sinter it in a hydrogen atmosphere. The specific sintering process is as follows: first, heat up to 200℃ and hold for 2 h; then heat up to 400℃ and hold for 2 h; then heat up to 600℃ and hold for 2 h; then heat up to 800℃ and hold for 2 h; finally, heat up to 920℃ and hold for 4 h. S3. The sintered ingot is heated to 860°C under hydrogen protection and hot-extruded into wire using a forward extrusion press. Then it is drawn to the required specifications to obtain silver-nickel contact material.

[0033] Example 6 A method for preparing a silver-nickel contact material with high resistance to high current surges includes the following steps: S1. Mix 99.55 kg of high-purity electrolytic silver ingot, 0.15 kg of high-purity electrolytic cerium ingot and 0.3 kg of high-purity electrolytic copper ingot, and then smelt, atomize and pulverize them. After drying, pass them through a 300-mesh sieve to obtain silver alloy powder. S2. Mix 74 kg of silver alloy powder, 24 kg of nickel powder with a Fisher particle size of 4 μm and 2 kg of silver tungstate powder with a particle size of 3 μm evenly to obtain a mixed powder. Then, pressurize it at 170 MPa for 90 s to form an ingot. Then, sinter it in a hydrogen atmosphere. The specific sintering process is as follows: first, heat up to 200℃ and hold for 2 h; then heat up to 400℃ and hold for 2 h; then heat up to 600℃ and hold for 2 h; then heat up to 800℃ and hold for 2 h; finally, heat up to 920℃ and hold for 4 h. S3. The sintered ingot is heated to 860°C under hydrogen protection and hot-extruded into wire using a forward extrusion press. Then it is drawn to the required specifications to obtain silver-nickel contact material.

[0034] Example 7 A method for preparing a silver-nickel contact material with high resistance to high current surges includes the following steps: S1. Mix 99.55 kg of high-purity electrolytic silver ingot, 0.15 kg of high-purity electrolytic cerium ingot and 0.3 kg of high-purity electrolytic copper ingot, and then smelt, atomize and pulverize them. After drying, pass them through a 300-mesh sieve to obtain silver alloy powder. S2. Mix 88 kg of silver alloy powder, 10 kg of nickel powder with a Fisher particle size of 4 μm and 2 kg of silver tungstate powder with a particle size of 3 μm evenly to obtain a mixed powder. Then, press it at 170 MPa for 90 s to form an ingot. After that, sinter it in a hydrogen atmosphere. The specific sintering process is as follows: first, heat up to 200℃ and hold for 2 h; then heat up to 400℃ and hold for 2 h; then heat up to 600℃ and hold for 2 h; then heat up to 800℃ and hold for 2 h; finally, heat up to 920℃ and hold for 4 h. S3. The sintered ingot is heated to 860°C under hydrogen protection and hot-extruded into wire using a forward extrusion press. Then it is drawn to the required specifications to obtain silver-nickel contact material.

[0035] Comparative Example 1 The difference from Example 3 is that the first additive is not added; otherwise, it is the same as Example 3. The specific steps are as follows: a. Mix 83.5 kg of silver powder, 15 kg of nickel powder with a Fisher particle size of 4 μm and 1.5 kg of silver tungstate powder with a particle size of 3 μm evenly to obtain a mixed powder. Then, pressurize it at 170 MPa for 90 s to form an ingot. Then, sinter it in a hydrogen atmosphere. The specific sintering process is as follows: first, heat up to 200℃ and hold for 2 h; then heat up to 400℃ and hold for 2 h; then heat up to 600℃ and hold for 2 h; then heat up to 800℃ and hold for 2 h; finally, heat up to 920℃ and hold for 4 h. b. The sintered ingot is heated to 860°C under hydrogen protection and hot-extruded into wire using a forward extrusion press. Then it is drawn to the required specifications to obtain silver-nickel contact material.

[0036] Comparative Example 2 The difference from Example 3 is that no second additive powder is added; otherwise, it is the same as Example 3. The specific steps are as follows: (1) Mix 99.55 kg of high-purity electrolytic silver ingot, 0.15 kg of high-purity electrolytic cerium ingot and 0.3 kg of high-purity electrolytic copper ingot, and then smelt, atomize and pulverize them. After drying, pass them through a 300-mesh sieve to obtain silver alloy powder. (2) Mix 85 kg of silver alloy powder and 15 kg of nickel powder with a Fisher particle size of 4 μm evenly to obtain a mixed powder. Then, press it under a pressure of 170 MPa for 90 s to form an ingot. Then, sinter it under a hydrogen atmosphere. The specific sintering process is as follows: first, heat up to 200℃ and hold for 2 h; then heat up to 400℃ and hold for 2 h; then heat up to 600℃ and hold for 2 h; then heat up to 800℃ and hold for 2 h; finally, heat up to 920℃ and hold for 4 h. S3. The sintered ingot is heated to 860°C under hydrogen protection and hot-extruded into wire using a forward extrusion press. Then it is drawn to the required specifications to obtain silver-nickel contact material.

[0037] Comparative Example 3 The difference from Example 3 is that the first additive is not added to the material in the form of silver alloy powder; otherwise, it is the same as Example 3. The specific steps are as follows: I. Ball mill and mix 99.55 kg of silver powder, 0.15 kg of cerium powder and 0.3 kg of copper powder until homogeneous; II. Mix 83.5 kg of the product obtained in step I, 15 kg of nickel powder with a Fisher particle size of 4 μm, and 1.5 kg of silver tungstate powder with a particle size of 3 μm evenly to obtain a mixed powder. Then, press the powder under a pressure of 170 MPa for 90 s to form an ingot. After that, sinter it in a hydrogen atmosphere. The specific sintering process is as follows: first, heat the powder to 200℃ and hold it for 2 h; then heat the powder to 400℃ and hold it for 2 h; then heat the powder to 600℃ and hold it for 2 h; then heat the powder to 800℃ and hold it for 2 h; finally, heat the powder to 920℃ and hold it for 4 h. III. The sintered ingot is heated to 860°C under hydrogen protection and hot-extruded into wire using a forward extrusion press. Then it is drawn to the required specifications to obtain silver-nickel contact material.

[0038] Comparative Example 4 The difference from Example 3 is that the second additive powder is not added to the material in the form of a compound powder; otherwise, it is the same as Example 3. The specific steps are as follows: A. Mix 99.55 kg of high-purity electrolytic silver ingot, 0.15 kg of high-purity electrolytic cerium ingot and 0.3 kg of high-purity electrolytic copper ingot, and then smelt, atomize and pulverize them. After drying, pass them through a 300-mesh sieve to obtain silver alloy powder. B. Mix 83.5 kg of silver alloy powder, 15 kg of nickel powder with a Fisher particle size of 4 μm, and 1.5 kg of tungsten-molybdenum alloy powder with a particle size of 3 μm evenly to obtain a mixed powder. Then, pressurize it at 170 MPa for 90 s to form an ingot. After that, sinter it in a hydrogen atmosphere. The specific sintering process is as follows: first, heat up to 200℃ and hold for 2 h; then heat up to 400℃ and hold for 2 h; then heat up to 600℃ and hold for 2 h; then heat up to 800℃ and hold for 2 h; finally, heat up to 920℃ and hold for 4 h. C. The sintered ingot is heated to 860°C under hydrogen protection and hot-extruded into wire using a forward extrusion press. Then it is drawn to the required specifications to obtain silver-nickel contact material.

[0039] Performance testing 1. The hardness and tensile strength of the silver-nickel contact materials prepared in the above embodiments and comparative examples were tested according to Parts 2 and 4 of JB / T 7780 "Test Methods for Mechanical and Physical Properties of Wires for Rivet-type Contacts". The test results are shown in Table 1.

[0040] 2. The silver-nickel contact materials prepared in the above examples and comparative examples were tested for AC-4 electrical performance using an STK-80E contact material electrical performance testing machine. The test parameters were as follows: test voltage AC400V; test current 6×18A; power factor 0.35; energizing time 0.05s; operating frequency 300 times / h; electrical life requirement ≥30000 cycles. The test results are shown in Table 1.

[0041] Table 1 Material physical properties and electrical lifetime

[0042] Data Analysis: As can be seen from Table 1, the hardness of Examples 1-7 of this application is at least 75 HV and can reach more than 95 HV. The tensile strength is at least 330 MPa and can reach more than 380 MPa. The measured electrical life is 34869-59317 cycles. The experimental data show that the silver-nickel contact material prepared in this application has high hardness and tensile strength, thus it has good anti-splashing ability, arc burn resistance, high current impact resistance and fusion welding resistance, and can meet the environment of large surge current impact of electrical appliances.

[0043] The difference between Comparative Examples 1-2 and Example 3 is that neither the first additive nor the second additive powder was added. As can be seen from Table 1, the hardness, tensile strength, and measured electrical lifetime cycles of Comparative Examples 1-2 are lower than those of Example 3. The experimental results show that the addition of the first additive and the second additive powder strengthens the silver matrix and improves the wettability between material interfaces. This not only improves the wear resistance of the material, but also improves its anti-splashing ability, arc burn resistance, high current impact resistance, and fusion welding resistance, enabling it to meet the environment of large surge current impact of electrical appliances.

[0044] The difference between Comparative Example 3 and Example 3 is that the first additive was not first melted and atomized with silver powder to form silver alloy powder before being added to the material. As can be seen from Table 1, the hardness, tensile strength and measured electrical lifetime of Comparative Example 3 are all lower than those of Example 3 to a certain extent. In particular, the measured electrical lifetime is significantly lower than that of Example 3. The experimental results show that compared with directly mixing silver powder, nickel powder and additive powder through physical mixing, adding the first additive to the material in the form of silver alloy powder can significantly improve the uniformity of the material composition, thereby making the material performance better.

[0045] The difference between Comparative Example 4 and Example 3 is that the second additive powder was not added to the material in the form of a compound. As can be seen from Table 1, the hardness, tensile strength and measured electrical lifetime of Comparative Example 4 are all lower than those of Example 3 to a certain extent. In particular, the measured electrical lifetime is significantly lower than that of Example 3. The experimental results show that, compared with directly adding the second additive powder to the material in the form of an alloy, adding the high-melting-point second additive powder to the silver-nickel contact material in the form of a compound powder can improve the interfacial wettability between materials. This not only improves the sinterability of the material and ensures the processing plasticity of the material, but also further improves the material's anti-spatter ability, arc burn resistance, high current impact resistance and anti-welding ability.

[0046] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for preparing a silver-nickel contact material with high resistance to high current surges, characterized in that, Includes the following steps: S1. Silver and the first additive are mixed, smelted, atomized, and powdered, then dried and sieved to obtain silver alloy powder; the first additive includes one or more of nickel, copper, lanthanum, cerium, and yttrium; S2. The silver alloy powder, nickel powder and the second additive powder are mixed evenly to obtain a mixed powder, which is then cold isostatically pressed into an ingot, and then sintered in a hydrogen atmosphere; the second additive powder includes silver tungstate powder and / or silver molybdate powder. S3. The sintered ingot is hot-extruded into wire and then drawn to obtain silver-nickel contact material.

2. The method for preparing a silver-nickel contact material with high resistance to high current surges according to claim 1, characterized in that, In step S1, the amount of the first additive is 0.1-0.8% of the total mass of silver and the first additive.

3. The method for preparing a silver-nickel contact material with high resistance to high current surges according to claim 1, characterized in that, In S2, by mass percentage, the mixed powder contains 8-40% nickel powder, 1-2% second additive powder, and the remainder is silver alloy powder.

4. The method for preparing a silver-nickel contact material with high resistance to high current surges according to claim 3, characterized in that, The nickel powder has a Fisher particle size of 2-8 μm, and the second additive powder has a particle size of 1-5 μm.

5. The method for preparing a silver-nickel contact material with high resistance to high current surges according to claim 1, characterized in that, The specific sintering conditions in S2 are: sintering at a temperature of 200-920℃ for 10-16 hours.

6. The method for preparing a silver-nickel contact material with high resistance to high current surges according to claim 1, characterized in that, The heating temperature for hot extrusion in S3 is 800-920℃.

7. A silver-nickel contact material with high resistance to high current surges, characterized in that, The silver-nickel contact material with high resistance to high current surges is prepared by the method described in any one of claims 1-6.

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