Method for preparing mixed rare-earth oxide modified silver tin oxide electrical contact material

Abstract

The invention discloses a method for preparing a mixed rare-earth oxide modified silver tin oxide electrical contact material, which comprises the following steps of: 1, treating Ag2O powder; 2, preparing alloy melt by alloying Sn, rare-earth element and Ag; 3, preparing a composite material by spray co-deposition; 4, performing in-situ chemical treatment on the composite material; and 5, preparing the mixed rare-earth oxide modified silver tin oxide electrical contact material by extruding, rolling and drawing. The preparation of the mixed rare-earth oxide modified silver tin oxide electrical contact material with short flow, near formation and enforced uniform solidification can be realized by integrating advanced processing technology of spray co-deposition, in-situ chemical reaction and the like. The mixed rare-earth oxide modified silver tin oxide electrical contact material prepared by adopting the method has high welding resistance and arc burning tolerance, and meanwhile has the characteristics of low temperature rise, simple subsequent processing, wide application range, long service life and capability of realizing industrialized production.

Description

technical field [0001] The invention belongs to the technical field of composite materials, and in particular relates to a preparation method of a silver tin oxide electrical contact material modified by mixed rare earth oxides. Background technique [0002] AgCdO electrical contact materials (including CdO: 8% to 15%) have been widely used at home and abroad for a long time. It has the characteristics of good corrosion resistance, strong welding resistance, low and stable contact resistance, etc., so it has good performance and is widely used. Used in low and medium voltage electrical appliances of several volts to several thousand volts, it is called "universal electrical contact material". However, due to the existence of cadmium and its compounds, the production, use and recycling of AgCdO materials are faced with the problem of "cadmium poisoning" pollution and harm to human health. Developed countries in Europe and the United States have clearly proposed to prohibit th...

AI Technical Summary

Problems solved by technology

[0003] Known AgSnO 2 There are obvious deficiencies in the preparation methods of electrical contact materials, mainly as follows: the preparation of AgSnO by powder metallurgy 2 When electrically contacting materials, the process is complicated and the production cost is high. After sintering, Ag and SnO 2 The interface bonding of the material is poor, which increases the brittleness of the material, which leads to an increase in the subsequent processing steps of the material, complex processes, and is not conducive to large-scale production; the preparation of AgSnO by internal oxidation method 2 When the material is electrically contacted, dense SnO will be generated on the surface of the AgSn alloy 2 layer to prevent the alloy from continuing to oxidize, so it is necessary to add indium (In) to promote the internal oxidation of the alloy, but the price of In is expensive, the resource reserve is less, and the cost is higher; the chemical precipitation method prepares AgSnO 2 When electrically contacting materials, there are pollution problems of acid, alkali and salt, and its production cycle is long, the cost is high, and there is also the problem of poor silver-tin dioxide interface bonding

[0004] Patent CN1082235C announced on April 3, 2002 discloses a synthesis method for preparing silver-tin dioxide electrical contact materials. Although this method can better solve the problem of the reaction interface, it needs to be mixed for a long time and many times. Sintering, the process is complicated, and the particle size and purity of the raw materials are high, which increases the production cost; in addition, the AgSnO prepared by this method 2 The grain size is large, and subsequent processing is still very difficult; in addition, there is still room for improvement in terms of high temperature rise of the material