Preparation method of refined silver tin oxide crystal grain

Abstract

The invention provides a preparation method of refined silver tin oxide crystal grains, which comprises the following steps: (1) performing water atomization of Ag and Sn, or performing water atomization of Ag, Sn, and additives to obtain AgSn powder; (2) mixing the AgSn powder with oxidation powder to obtain AgSn mixed powder; (3) pressing the AgSn mixed powder through isostatic pressing to obtain an AgSn ingot; (4) extruding the AgSn ingot to obtain AgSn wires, drawing, punching, and oxidizing the wires; (5) performing compression and extrusion of the oxidized wires, drawing to obtain AgSnO2 wires. Compared with previous preparation methods in which AgSn ingots are cast by an alloy phase of multiple elements of Ag / Sn / Cu, are extruded into wires, and are oxidized internally, the preparation method of the invention provides higher oxygen content of AgSn wires, and more dislocation; wire oxidation is performed later, which can reduce the oxidation energy barrier, and refine the crystal boundary and the crystal grain; the smaller the crystal boundary is, the more uniformly the oxide particles distribute on a silver matrix; the smaller the oxide particles are, the better the melting welding resistance is; and the risk of incomplete oxidation is reduced.

Description

technical field [0001] The invention belongs to the field of metal matrix composite materials, and in particular relates to a preparation method for refining silver tin oxide grains. Background technique [0002] Silver tin oxide electrical contact materials are mainly used in electrical switches such as relays, contactors, motors, switches, etc. This material is one of the environmentally friendly materials commonly used in low-voltage electrical appliances. With the development of miniaturization of relays, the life expectancy of electrical appliances and the improvement of resistance to large currents, etc., various material manufacturers have shown their talents in order to improve the resistance to welding and anti-burning of materials. The main manufacturing methods are: Preparation methods such as pre-oxidation method, internal oxidation method, traditional powder mixing method and chemical method. Each of these methods has its own advantages. The types of additives...

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Problems solved by technology

The above documents 1) and 3) were doped with TiO by electroless plating 2 , rare earth elements to achieve the effect of grain refinement and the method of coating tin oxide particles in silver ammonia solution, both of which belong to chemical methods, and the materials prepared by this method have low strength and poor compactness

Document 2) The material is prepared by the atomization (pre-oxidation) method. In this method, materials with different oxidation states show different characteristics, and the oxide content is high, and its processing performance is very poor.

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