Silver-iron oxide electric contact material with dispersed oxide particles and preparation method thereof

Abstract

The invention discloses a silver-iron oxide electric contact material with dispersed oxide particles and a preparation method of the silver-iron oxide electric contact material. The preparation methodcomprises the following steps: (1) smelting silver and modified additive metal, and carrying out water atomization to form alloy powder; (2) drying and sieving the alloy powder through a 200-mesh sieve to prepare -200 mesh alloy powder; (3) mixing the -200 mesh atomized alloy powder with iron powder; (4) performing powder rolling on the powder mixed in the step (3) to form a strip; (5) annealingthe strip, and then further performing cold rolling; and (6) carrying out internal oxidation on the rolled strip, then carrying out punching, ingot pressing, sintering and re-pressing on the strip subjected to internal oxidation, and further carrying out hot extrusion to form a plate or a wire. The silver-iron oxide electric contact material prepared by the method is fine in oxide particle size and uniform in structure, the material yield is remarkably improved compared with that of a conventional multi-extrusion process, and the method is suitable for mass production.

Description

technical field [0001] The invention belongs to the technical field of electric contacts, and specifically refers to a silver iron oxide electric contact material with dispersed oxide particles and a preparation method thereof. Background technique [0002] In the existing electrical contact field, silver-based electrical contact materials are currently the most widely used type of material. This is because silver has high electrical conductivity, thermal conductivity, and good mechanical processing characteristics; and because silver oxide is unstable at high temperatures, it is easy to decompose into simple silver and oxygen, so it can ensure low and stable contact resistance of silver-based electrical contact materials . [0003] At present, silver-based electrical contact materials are mainly divided into three categories: silver-metal oxides, silver-based pseudoalloys, and silver-based alloys. Among them, silver metal oxides play an important role in the entire electri...

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Problems solved by technology

The brief technological process for the preparation of silver iron oxide powder metallurgy is as follows: silver powder, iron oxide powder, additive powder mixing - isostatic pressing - sintering - repressing - hot extrusion into plates or wires, the main disadvantages of this production process: The raw material powder particles are small and easy to agglomerate, and the iron oxide and additive particles cannot be fully dispersed during the mixing process. Therefore, the defects of oxide or additive powder aggregation and uneven distribution cannot be avoided in the finished product, which further affects the quality of the material. Electrical performance stability

In this method, because the synthesized metal carbonate is precipitated in flocculent form and the precipitate is relatively fluffy, the cleaning process cannot effectively remove the low melting point impurity sodium introduced by the addition of the sedimentation agent, and finally the content of low melting point impurity sodium in the finished material is relatively high. As a result, the material exhibits higher arcing energy and longer arcing time during the opening and closing process of the electrical test, which ultimately affects the anti-arc burning ability of the material itself

[0006] Although the process method adopted in the above-mentioned patent can solve the problem of oxide particle aggregation, it introduces impurity metals with low melting point that cannot be removed in the subsequent cleaning process; while the traditional powder metallurgy process cannot effectively achieve iron oxide particles and Uniform dispersion of additive particles

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