Silver-saving special alloy contact

Abstract

The invention relates to the technical field of electric contact materials, in particular to a silver-saving special alloy contact. The silver-saving type special alloy contact comprises a copper-based material and Fe3Al; and further comprises transition element metals of group 5 and group 6 in the periodic table of elements. By adding a certain amount of Fe3Al into the electrical contact material, the conductivity of the copper-based electrical contact is remarkably improved, so that the working temperature is reduced, and the oxidation resistance and fusion welding resistance of the electrical contact can be effectively improved. Meanwhile, transition element metal capable of playing an auxiliary role is selected through multiple experiments, the hardness of the copper-based electrical contact is remarkably improved, and the transition element metal and Fe3Al generate a good synergistic effect. The special alloy contact material has the advantages of being environmentally friendly, high in performance and low in cost, the high performance can be improved with low cost consumption, the special alloy contact material is expected to replace a silver-based electric contact material on a low-voltage electric appliance, and the special alloy contact material is suitable for application and popularization in practice.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical contact materials, and particularly to a silver-saving special alloy contact Background Art

[0002] Electrical contacts are key components in high- and low-voltage electrical appliances, relays, contactors, circuit breakers, etc., playing the role of transmitting and interrupting current. Their performance directly affects the reliability and service life of switches and electrical appliances. Silver-based electrical contact materials are widely used in weak current environments. As a precious metal, silver has a relatively high cost in industrial production, especially in the electrical contact material industry with a large amount of silver used.

[0003] The characteristics of electrical switches for small household appliances (AC breaking type) are small current, small contact surface, frequent arcing, and easy generation of oxide films. Therefore, although the existing copper-based contacts have a relatively low cost when applied in AC breaking type household appliance switches, the biggest problem is that the switches are frequently turned on and off, making it easy to generate oxide films at the contacts, resulting in an increase in contact resistance. In addition, the existing copper-based contacts have poor anti-ablation ability and no or poor arc extinguishing ability. Therefore, it is necessary to develop a contact with strong breaking ability, strong oxidation resistance, high ablation resistance and wear resistance on the premise of relatively low cost.

[0004] For example, as disclosed in Patent CN100354999C, a clean and environment-friendly copper-based contact material for low-voltage electrical appliances and its contact preparation method. This technical solution adds pure rare earth oxides or mixed rare earth oxides to the contact material, and the made contacts have good oxidation resistance and long electrical life. Another example is the copper-based electrical contact material for low-voltage electrical appliances and its preparation method disclosed in Patent CN106683914B. This technical solution adds rare earth element Ce to the contact material to improve mechanical, oxidation resistance and electrical contact performance. However, rare earth elements are used in the above technical solutions, and improper addition may result in the risk that the hardness of the contact does not meet the standard. In addition, the manufacturing process involves multiple steps of processing (such as repressing, resintering, extruding, rolling), which consumes a lot of energy, causes a large amount of pollution, and the cost-saving effect is not obvious. Summary of the Invention

[0005] The present invention aims to overcome the defects of existing silver-free or less-silver electrical contacts, such as easy oxidation, easy corrosion, and short service life, and provides a silver-saving special alloy contact to overcome the above defects.

[0006] To achieve the above object of the present invention, the present invention is realized through the following technical solutions: In a first aspect, the present invention discloses a silver-saving special alloy contact, which comprises a copper-based material and Fe3Al; It further comprises transition element metals of Group 5 and Group 6 in the periodic table.

[0007] Copper is currently difficult to replace silver in various application fields as an electrical contact material. The biggest problem lies in the poor high-temperature oxidation resistance of copper contacts. Once an oxide film forms on the surface of the copper contact, the contact resistance of the contact will increase, causing the temperature rise of the electrical appliance to be too high, and in severe cases, the electrical appliance will fail. The copper used for contact materials usually contains a certain amount of impurities, which come from the smelting residues in the raw materials or the pollution during the processing. Some impurities with extremely low solid solubility, such as lead and bismuth, segregate at grain boundaries in the copper matrix, forming eutectic phases with low melting points (such as Cu-Pb), resulting in certain thermal brittleness of the manufactured contacts, making them prone to failure at high temperatures, accelerating arc erosion in AC break-type household electrical appliance switches, and greatly shortening the life of the switches. Moreover, these impurities cause lattice distortion in the copper matrix, strongly scatter the conduction electrons, and have a great impact on the electrical conductivity.

[0008] In the present invention, a certain amount of Fe3Al is added to the copper-based contact. Due to the characteristics of its intermetallic compound, it can form high-melting-point compounds with some harmful impurities dissolved in copper, reducing the lattice distortion caused by impurity particles, thereby reducing the scattering of conduction electrons and increasing the electrical conductivity. In the field of low-voltage electrical appliances, higher electrical conductivity means lower operating temperature and higher usage safety. At the same time, the addition of Fe3Al, due to the special properties of its intermetallic compound, in the intermetallic compound, the bonding between atoms has both metallic bonds, covalent bonds, and ionic bonds, and the arrangement of its atoms follows a certain highly ordered pattern. When it exists as fine particles in the structure of the metal alloy, it will increase the overall hardness of the metal alloy.

[0009] In addition, the present invention also adds transition element metals of Groups 5 and 6 in the periodic table to the contact material. First of all, generally speaking, the melting points of transition element metals of Groups 5 and 6 are relatively high. The melting point of Fe3Al is about 1540°C–1600°C. The high-melting-point metals cooperate with Fe3Al, making the electrical contact not easily melt at the high temperature of the arc. Secondly, some transition element metals of Groups 5 and 6 have relatively high hardness, increasing the overall hardness of the electrical contact. Finally, the transition element metals of Groups 5 and 6 have extremely low solid solubility in the copper matrix, so they exist as dispersed particles in the copper matrix, thereby improving the anti-welding property and hardness of the electrical contact while avoiding lattice distortion of the copper matrix and maintaining a relatively high electrical conductivity of copper.

[0010] Further, the transition element metals include one or more combinations of V, Nb, Ta, Cr, Mo, and W. These transition element metals have extremely low solid solubility, which enables them to improve the hardness of the electrical contact while having a relatively small reduction in electrical conductivity. Through multiple experiments, it has been found that among the above transition element metals, the electrical contact performance is better when Cr and Nb are added. The possible reasons are as follows: First, Cr and Nb mutually reduce their respective solid solubilities, which can increase the overall electrical conductivity of the material and partially reduce plasticity. Second, due to the strengthening effect of the covalent bond compound bonding on the particle surface, a stronger connection is formed between the Fe3Al particles and the Cr-containing copper solid solution, thereby obtaining an improvement in the material hardness under long-term cyclic loading conditions. Third, the oxide formed by Nb can form a passivation film, enhancing the corrosion resistance of the alloy.

[0011] Further, in terms of mass percentage, the Fe3Al and the transition element metals account for 4 - 10% of the total amount.

[0012] Further, the copper-based material is one or a combination of two of pure copper and copper alloy.

[0013] Further, the copper alloy is composed of one or more of Cu and Ni, Mo, Mg, Zn, W, Ti, In, La, Zr, Al, SnO2, ZnO2, In2O3, TiC, WC, diamond, graphite, and graphene.

[0014] In the second aspect, the present invention also discloses a preparation method of the above silver-saving type special alloy electrical contact, including the following steps: S1. Grind the copper-based material, transition element metals, and Fe3Al and mix them evenly to obtain a raw material mixed powder; S2. Put the raw material mixed powder into a steel jacket, perform a vacuum pretreatment, and heat it; S3. Perform hot isostatic pressing on the jacket under vacuum conditions to obtain a silver-saving type special alloy; S4. Extrude the silver-saving type special alloy to make the silver-saving type special alloy electrical contact.

[0015] In the third aspect, the present invention discloses the application of the above silver-saving type special alloy electrical contact in a disconnection type electrical switch.

[0016] In the fourth aspect, the present invention discloses the application of the above silver-saving type special alloy electrical contact in a circuit breaker.

[0017] Therefore, the present invention has the following beneficial effects: (1) By adding a certain amount of Fe3Al to the electrical contact material, the present invention significantly improves the electrical conductivity of the copper-based electrical contact, thereby reducing the working temperature and effectively improving the oxidation resistance and anti-welding performance of the electrical contact.

[0018] (2) Through multiple experiments, the present invention has selected transition element metals that can play an auxiliary role, significantly improving the hardness of the copper-based electrical contact and producing a good synergistic effect with Fe3Al.

[0019] (3) The special alloy contact material of the present invention has the characteristics of environmental protection, high performance, and low cost, and can achieve higher performance improvement with lower cost consumption, and is expected to replace the silver-based electrical contact material on low-voltage electrical appliances. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a comparison chart for the room-temperature antioxidant test. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The present invention will be further described below in conjunction with specific embodiments. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention involved in the following descriptions are usually only a part of the embodiments of the present invention, rather than all of the embodiments. Therefore, all other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0022] Example 1: Ratio of contact material: by mass percentage: Cr: 1%; Fe3Al: 1%; Nb: 2%; CuLa powder: 48%; CuZr powder 48%.

[0023] Among them, the La content in the CuLa powder is 0.8%; the Zr content in the CuZr powder is 0.5%.

[0024] The above raw materials are ball-milled on a ball mill for 12 hours, then put into a powder mixer and mixed for 8 hours. The mixed raw materials are put into a steel jacket for vacuum pretreatment at a temperature of 450 °C and a vacuum degree of 1×10 -3 Pa, and the exhaust pipe is welded and sealed when taking out of the furnace. The evacuated jacket is subjected to hot isostatic pressing at 1000 °C. The produced material is extruded into wire or strip by an extruder and further made into the shape of a contact.

[0025] Example 2: Cr: 1%; Fe3Al: 2%; Nb: 2%; CuLa powder: 47.5%; CuZr powder 47.5%.

[0026] Among them, the La content in the CuLa powder is 0.8%; the Zr content in the CuZr powder is 0.5%.

[0027] The above raw materials are ball-milled on a ball mill for 12 hours, then put into a powder mixer and mixed for 8 hours. The mixed raw materials are put into a steel jacket for pre-vacuum treatment at a temperature of 450 °C and a vacuum degree of 1×10 -3 Pa, and the exhaust pipe is welded and sealed when taken out of the furnace. The jacket with good vacuum is subjected to hot isostatic pressing at 1000 °C. The produced material is extruded into wire or strip by an extruder and further made into the shape of a contact.

[0028] Example 3: Cr: 2%; Fe3Al: 4%; Nb: 4%; CuLa powder: 45%; CuZr powder 45%.

[0029] Among them, the La content in the CuLa powder is 0.8%; the Zr content in the CuZr powder is 0.5%.

[0030] The above raw materials are ball-milled on a ball mill for 12 hours, then put into a powder mixer and mixed for 8 hours. The mixed raw materials are put into a steel jacket for pre-vacuum treatment at a temperature of 450 °C and a vacuum degree of 1×10 -3 Pa, and the exhaust pipe is welded and sealed when taken out of the furnace. The jacket with good vacuum is subjected to hot isostatic pressing at 1000 °C. The produced material is extruded into wire or strip by an extruder and further made into the shape of a contact.

[0031] Example 4: Cr: 1%; Fe3Al: 3%; Nb: 2%; Cu powder: 28.2% CuLa powder: 18.8%; CuZr powder 47%.

[0032] Among them, the La content in the CuLa powder is 0.8%; the Zr content in the CuZr powder is 0.5%.

[0033] The above raw materials are ball-milled on a ball mill for 10 hours, then put into a powder mixer and mixed for 6 hours. The mixed raw materials are put into a steel jacket for pre-vacuum treatment at a temperature of 550 °C and a vacuum degree of 1×10 -3 Pa, and the exhaust pipe is welded and sealed when taken out of the furnace. The jacket with good vacuum is subjected to hot isostatic pressing at 1100 °C. The produced material is extruded into wire or strip by an extruder and further made into the shape of a contact.

[0034] Example 5: Cr: 1%; Fe3Al: 4%; Nb: 2%; Cu powder: 27.9% CuLa powder: 37.2%; CuZr powder 27.9%.

[0035] Among them, the La content in CuLa powder is 0.8%; the Zr content in CuZr powder is 0.5%.

[0036] Ball-mill the above raw materials on a ball mill for 10 hours, then put them into a powder mixer and mix for 6 hours. Put the mixed raw materials into a steel jacket for pre-vacuum treatment at a temperature of 550 °C and a vacuum degree of 1×10 -3 Pa, then weld the exhaust pipe shut. The jacket with good vacuum is subjected to hot isostatic pressing at 1100 °C. The produced material is extruded into wire or strip by an extruder and further made into the shape of a contact point.

[0037] Example 6: Cr: 0.25%; Fe3Al: 0.75%; Nb: 0.5%; Cu powder: 50% CuLa powder: 30%; CuZr powder 18.5%.

[0038] Among them, the La content in CuLa powder is 0.8%; the Zr content in CuZr powder is 0.5%.

[0039] Ball-mill the above raw materials on a ball mill for 10 hours, then put them into a powder mixer and mix for 6 hours. Put the mixed raw materials into a steel jacket for pre-vacuum treatment at a temperature of 550 °C and a vacuum degree of 1×10 -3 Pa, then weld the exhaust pipe shut. The jacket with good vacuum is subjected to hot isostatic pressing at 1100 °C. The produced material is extruded into wire or strip by an extruder and further made into the shape of a contact point.

[0040] Comparative Example 1: Proportion of contact material: by mass percentage: Cr: 2%; Nb: 2%; CuLa powder: 48%; CuZr powder 48%.

[0041] Among them, the La content in CuLa powder is 0.8%; the Zr content in CuZr powder is 0.5%.

[0042] The above raw materials are ball-milled on a ball mill for 12 hours, then put into a powder mixer and mixed for 8 hours. The mixed raw materials are put into a steel jacket for pre-vacuum treatment at a temperature of 450 °C and a vacuum degree of 1×10 -3 Pa, and then the exhaust pipe is welded and sealed when taken out of the furnace. The jacket with good vacuum is subjected to hot isostatic pressing at 1000 °C. The produced material is extruded into wire or strip by an extruder and further made into the shape of a contact.

[0043] Comparative Example 2: Proportion of contact material: by mass percentage: Fe3Al: 4%; CuLa powder: 48%; CuZr powder 48%.

[0044] Among them, the La content in the CuLa powder is 0.8%; the Zr content in the CuZr powder is 0.5%.

[0045] The above raw materials are ball-milled on a ball mill for 12 hours, then put into a powder mixer and mixed for 8 hours. The mixed raw materials are put into a steel jacket for pre-vacuum treatment at a temperature of 450 °C and a vacuum degree of 1×10 -3 Pa, and then the exhaust pipe is welded and sealed when taken out of the furnace. The jacket with good vacuum is subjected to hot isostatic pressing at 1000 °C. The produced material is extruded into wire or strip by an extruder and further made into the shape of a contact.

[0046] Comparative Example 3: Proportion of contact material: by mass percentage: Cr: 2% Fe3Al: 2%; CuLa powder: 48%; CuZr powder 48%.

[0047] Among them, the La content in the CuLa powder is 0.8%; the Zr content in the CuZr powder is 0.5%.

[0048] The above raw materials are ball-milled on a ball mill for 12 hours, then put into a powder mixer and mixed for 8 hours. The mixed raw materials are put into a steel jacket for pre-vacuum treatment at a temperature of 450 °C and a vacuum degree of 1×10 -3 Pa, and then the exhaust pipe is welded and sealed when taken out of the furnace. The jacket with good vacuum is subjected to hot isostatic pressing at 1000 °C. The produced material is extruded into wire or strip by an extruder and further made into the shape of a contact.

[0049] Comparative Example 4: Proportion of contact material: by mass percentage: Fe3Al: 2%; Nb: 2%; CuLa powder: 48%; CuZr powder 48%.

[0050] Among them, the La content in the CuLa powder is 0.8%; the Zr content in the CuZr powder is 0.5%.

[0051] The above raw materials are ball-milled on a ball mill for 12 hours, then put into a powder mixer and mixed for 8 hours. The mixed raw materials are put into a steel jacket for pre-vacuum treatment at a temperature of 450 °C and a vacuum degree of 1×10 -3 Pa, and the exhaust pipe is welded shut when taken out of the furnace. The jacket with good vacuum is subjected to hot isostatic pressing at 1000 °C. The produced material is extruded into wire or strip by an extruder and further made into the shape of a contact.

[0052] Comparative Example 5: Proportion of contact material: by mass percentage: Cr: 3%; Fe3Al: 3%; Nb: 6%; CuLa powder: 44%; CuZr powder 44%.

[0053] Among them, the La content in the CuLa powder is 0.8%; the Zr content in the CuZr powder is 0.5%.

[0054] The above raw materials are ball-milled on a ball mill for 12 hours, then put into a powder mixer and mixed for 8 hours. The mixed raw materials are put into a steel jacket for pre-vacuum treatment at a temperature of 450 °C and a vacuum degree of 1×10 -3 Pa, and the exhaust pipe is welded shut when taken out of the furnace. The jacket with good vacuum is subjected to hot isostatic pressing at 1000 °C. The produced material is extruded into wire or strip by an extruder and further made into the shape of a contact.

[0055] Comparative Example 6: Proportion of contact material: by mass percentage: Cr: 0.1%; Fe3Al: 0.3%; Nb: 0.1%; CuLa powder: 49%; CuZr powder 48.5%.

[0056] Among them, the La content in the CuLa powder is 0.8%; the Zr content in the CuZr powder is 0.5%.

[0057] The above raw materials are ball-milled on a ball mill for 12 hours, then put into a powder mixer and mixed for 8 hours. The mixed raw materials are put into a steel jacket for pre-vacuum treatment at a temperature of 450 °C and a vacuum degree of 1×10 -3The exhaust pipe of the Pa furnace is welded and sealed. The evacuated cladding is subjected to hot isostatic pressing at 1000 °C. The produced material is extruded into wire or strip by an extruder and further formed into the shape of a contact.

[0058] Comparative Example 7: Proportion of contact material: by mass percentage: CuLa powder: 50%; CuZr powder 50%.

[0059] Among them, the La content in the CuLa powder is 0.8%; the Zr content in the CuZr powder is 0.5%.

[0060] The above raw materials are ball milled for 12 hours on a ball mill, then put into a powder mixer and mixed for 8 hours. The mixed raw materials are put into a steel cladding for vacuum pretreatment at a temperature of 450 °C and a vacuum degree of 1×10 -3 The exhaust pipe of the Pa furnace is welded and sealed. The evacuated cladding is subjected to hot isostatic pressing at 1000 °C. The produced material is extruded into wire or strip by an extruder and further formed into the shape of a contact.

[0061] In the electrical contacts of the examples and comparative examples, by mass percentage, the proportions of each component are shown in Table 1: Group Cr（%） <![CDATA[Fe3Al (%)]]> Nb (%) Cu Powder (%) CuLa Powder (%) CuZr Powder (%) Example 1 1 1 2 0 48 48 Example 2 1 2 2 0 47.5 47.5 Example 3 2 4 4 0 45 45 Example 4 1 3 2 28.2 18.8 47 Example 5 1 4 2 27.9 37.2 27.9 Example 6 0.25 0.75 0.5 50 30 18.5 Comparative Example 1 2 0 2 0 48 48 Comparative Example 2 0 4 0 0 48 48 Comparative Example 3 2 2 0 0 48 48 Comparative Example 4 0 2 2 0 48 48 Comparative Example 5 3 3 6 0 44 44 Comparative Example 6 0.1 0.3 0.1 0 49 48.5 Comparative Example 7 0 0 0 0 50 50 The density, hardness, and resistivity of the contacts made in the above examples and comparative examples are respectively tested, and a normal temperature antioxidant experiment and an electrical life experiment are carried out.

[0062] Normal temperature antioxidant experiment: The electrical contacts of the examples and comparative examples are cut to 1 square centimeter and placed at room temperature under the condition of air humidity of 40%-50%. After 30 days, the oxidation color situation on the surface of the electrical contacts is recorded. If there is only a tiny oxidation color on the contact surface, it is called "extremely little oxidation"; if the oxidation color area is about 5%-25%, it is called "less oxidation"; if the oxidation color area is 25%-50%, it is called "more oxidation"; if the oxidation color area is greater than 50%, it is called "severe oxidation".

[0063] Electrical life experiment: It is carried out according to the detection method described in Chapter 19 "Normal operation" of GB / T 16915.1-2024. The test current is 10 A, the connection wire specification is 2.5 mm²×1 mm, the ambient temperature is +20~25 °C, and the contacts are continuously switched on and off. When the following situations occur, stop the switching and record the number of switchings: The contacts show wear that is not conducive to continued use, the electrical connection or mechanical connection becomes loose, continuous arcing appears, and the contacts are welded. The test and experimental results are shown in Table 2: Group Density (g / cm³) Hardness (HV) Resistivity (μΩ•cm) Electrical Life (cycles) Antioxidant Experiment Example 1 8.71 128 2.42 44000 Very Little Oxidation Example 2 8.68 127 2.34 45300 Very Little Oxidation Example 3 8.60 133 2.38 48200 No Oxidation Example 4 8.66 126 2.28 47400 No Oxidation Example 5 8.68 118 2.22 46600 No Oxidation Example 6 8.78 115 2.30 41300 Very Little Oxidation Comparative Example 1 8.70 128 2.58 38000 More Oxidation Comparative Example 2 8.65 120 2.31 42800 More Oxidation Comparative Example 3 8.62 118 2.38 40100 Less Oxidation Comparative Example 4 8.65 116 2.35 40380 Less Oxidation Comparative Example 5 8.52 140 2.78 50080 Less Oxidation Comparative Example 6 8.77 110 2.24 36000 Severe Oxidation Comparative Example 7 8.74 112 2.32 38300 More Oxidation As can be seen from the test results in Table 2: Compared with Example 1, Fe3Al was not added in Comparative Example 1, resulting in a significant increase in resistivity and a significant decrease in conductivity; compared with Example 1, the transition element metals Cr and Nb were not added in Comparative Example 2, resulting in a serious decrease in the electrical contact density and hardness indexes, and the actual requirements of the electrical contact could not be met; the transition metal element of Group 5 was not added in Comparative Example 3, and the transition metal element of Group 6 was not added in Comparative Example 4, and the performance decreased severely compared with the example; too much Fe3Al and transition element metals were added in Comparative Example 5, although the hardness was increased, but the resistivity was too high; the addition amounts of Fe3Al and transition element metals in Comparative Example 6 were too small, resulting in a low overall hardness of the electrical contact; Comparative Example 7 was a commercially available common copper contact, which had good conductivity, but its oxidation resistance and electrical life were not as good as those of the special alloy contact in the example. As Figure 1 shown, after being placed for one month, the common copper contact had been severely oxidized, while the surface of the contact in Example 1 remained smooth. Based on the above experimental data, the silver-saving special alloy contact of the embodiment of the present invention has outstanding oxidation resistance and a long electrical life, has good conductivity and hardness, and has great application prospects in the scenario of frequent on-off of the switch.

[0064] Finally, it should be noted that: The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: They can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A silver-saving special alloy contact, characterized in that: It includes copper-based materials and Fe3Al; Also included are transition element metals from Groups 5 and 6 of the periodic table.

2. The silver-saving special alloy contact according to claim 1, characterized in that: The transition element metal includes one or more combinations of V, Nb, Ta, Cr, Mo, and W.

3. The silver-saving special alloy contact according to claim 2, characterized in that: In terms of mass percentage, the Fe3Al and the transition element metal account for 1-10% of the total amount.

4. The silver-saving special alloy contact according to claim 1, characterized in that: The copper-based material is pure copper, copper alloy or a combination of the two.

5. The silver-saving special alloy contact according to claim 4, characterized in that: The copper alloy is composed of Cu and one or more of Ni, Mo, Mg, Zn, W, Ti, In, La, Zr, Al, SnO2, ZnO2, In2O3, TiC, WC, diamond, graphite, and graphene.

6. A method for preparing a silver-saving special alloy contact according to any one of claims 1 to 5, characterized in that: The steps include: S1, grinding the copper-based material, transition element metal, and Fe3Al and mixing them evenly to obtain a raw material mixed powder; S2, placing the raw material mixed powder into a steel bag for pre-vacuum treatment and heating; S3, hot isostatic pressing the package under vacuum conditions to obtain a silver-saving special alloy; S4. Extruding the silver-saving special alloy to form the silver-saving special alloy contact.

7. The method for preparing a silver-saving special alloy contact according to claim 6, characterized in that: In step S2, the heating temperature is 450-650°C, and the vacuum degree is ≤1×10-3Pa.

8. The method for preparing a silver-saving special alloy contact according to claim 6, characterized in that: The temperature of hot isostatic pressing in step S3 is 900-1200°C.

9. Use of a silver-saving special alloy contact as claimed in any one of claims 1 to 5 in a disconnecting electrical switch.

10. Use of a silver-saving special alloy contact as claimed in any one of claims 1 to 5 in a circuit breaker.

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