Superfine oxide particle silver oxide ferroelectric contact material and preparation method thereof

Abstract

The invention discloses a superfine oxide particle silver oxide ferroelectric contact material and a preparation method thereof. The preparation method comprises the following steps of: (1) preparingcomposite metal salt precursor powder, uniformly mixing a metal salt solution, and then preparing the composite metal salt precursor powder from the metal salt solution subjected to pH adjustment on spray drying equipment; (2) calcining and decomposing the composite metal salt precursor powder prepared in the step (1) through step heating to prepare silver oxide composite powder, wherein the silver oxide composite powder contains superfine oxide particles; and (3) performing cold isostatic pressing, sintering, re-pressing and hot extrusion on the silver oxide composite powder prepared in the step (2) to form a plate or a wire of the superfine oxide particle silver oxide ferroelectric contact material. According to the scheme, uniform dispersion and superfine particle size of the oxide particles can be realized, and low-melting-point metal impurities are not introduced in the preparation process of the material.

Description

technical field [0001] The invention belongs to the technical field of electric contact materials, and specifically refers to an electric contact material of ultrafine oxide grain silver iron oxide 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 ele...

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Problems solved by technology

The brief process of powder metallurgy preparation of silver iron oxide is as follows: silver powder, iron oxide powder, additive powder mixing - isostatic pressing - sintering - repressing - hot extrusion into plate or wire, the main disadvantages of this production process: Because the raw material powder particles are small and easy to agglomerate, the iron oxide and additive particles cannot be fully dispersed during the mixing process, so 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 in the process of electrical properties, which ultimately affects the ability of the material itself to resist arc burning

[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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