Method for preparing silver tin oxide electrical contactor material containing additives

Abstract

The invention discloses a method for preparing silver tin oxide electrical contactor material containing additives. The method comprises the following steps: (1) calculating the dosages of needed tin dioxide powder, silver powder and salt compounds containing adding elements according to the compounding ratio of the silver tin oxide electrical contactor material needed to be prepared, and weighing for reserve; (2) preparing the salt compounds containing the adding elements into aqueous solution or ethanol solution, adding the tin dioxide powder or silver powder, mixing materials to obtain alloy powder sizing agents in which the salt compounds containing the adding elements are distributed evenly; (3) drying and smashing the sizing agents to obtain the alloy powder in which the salt compounds containing the adding elements are distributed evenly; (4) evenly mixing the obtained alloy powder and the silver powder or the tin dioxide powder, and performing the processes of isostatic pressing, sintering and extruding. In the method, the additives are added to matrices in a special mode, the problem of additive aliquation caused by the conventional powder mixing technology is resolved, and the densifying degree, the processing performance, the yield and the electrical performance of the materials are increased.

Description

technical field [0001] The invention relates to the field of metal-based composite materials, in particular to a method for preparing an additive-containing silver-tin oxide electrical contact material. Background technique [0002] From the perspective of environmental protection and human health, the universal silver cadmium oxide (AgCdO) contact material is gradually eliminated from the market. Silver tin oxide (AgSnO 2 ) is a new type of non-toxic electrical contact material that has developed rapidly in recent years, AgSnO 2 The contact material exhibits excellent wear resistance, welding resistance and arc erosion resistance, and the material has less migration and a uniform surface. At the same time, AgSnO 2 The electrical properties of the contact material are close to AgCdO. But AgSnO 2 The contact resistance of the contact material is relatively large and the temperature rises, which seriously affects the electrical performance and limits the application of its...

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Problems solved by technology

Among them, the mixed powder method is to mix Ag powder, SnO 2 And the additive powder powder is fully mixed, and then the material is extruded or molded into AgSnO 2 Contact material, in which the additives are added in the form of powder intermixing. This method is widely used by manufacturers due to its simple preparation method and short processing cycle. However, the prepared products have low electrical usability and are prone to additive segregation, etc. The problem is that it can only be applied to some low-end electrical appliances with low requirements; the internal oxidation method can be divided into powder pre-oxidation method and conventional internal oxidation method, and the powder pre-oxidation method mainly refers to passing the AgSn alloy powder containing additives through the powder Preparation of AgSnO with Additives by Bulk Oxidation 2 materials, and finally prepared into high-density AgSnO by extrusion or molding 2 Contact materials, but this process is easy to agglomerate during oxidation, the additives cannot be evenly distributed in the matrix, and the wettability of silver and tin oxide is not good; the internal oxidation method refers to the preparation of alloy wires after melting Ag, Sn, and additives material or plate, and then prepared into additive-containing AgSnO by internal oxidation process 2 Contact materials, but this process is prone to "poor oxide regions", which seriously affects its electrical life; chemical co-deposition mainly refers to the preparation of AgSnO by co-deposition process 2 The most representative contact material is to add a precipitant to the silver nitrate solution containing tin oxide powder. This method prepares AgSnO with more uniform structure and higher electrical properties. 2 However, processing the powder through chemical methods will cause serious pollution to the environment, and there are also disadvantages such as cumbersome process, high production cost, and long processing cycle.

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