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AgCdO material was once considered to be the best electrical contact material. it has fine performance of extinguishing arc, which was called the "universal contact" in the field of middle-load switches. However, with the harsh performance requirements such as going miniaturization, high-reliability, long life on the electrical contact, AgCdO material has shown the obvious insufficiency in anti-attrition, anti-melt weld, arc erosion-resistant and so on. Moreover, as its toxin, does not meet the environmental protection requirement. Because of its fine anti-arc erosion, wearability, switching and better anti-melt welds, AgSnO2 becomes the most promising substitute for AgCdO material.However, the machinability of AgSnO2 which was made by the conventional method is much worse than AgCdO. It is very prone to break in the wiredrawing situation. It will be unable to ensure the scale production. Moreover, It will be also more prone to crack in riveting process.The finite element method was used in this object. The extrusion process of AgSnO2 material was simulated. The distribution of particles, the relation of stress and strain, the velocity and displacement, and the force were analyzed. The last, comparing with experimental results, analyzing the law of deformation, it will offer an effective theoretical foundation for the industrialization manufacture of AgSnO2 material.In this paper, MSC.Marc finite element software was used to simulate the extrusion of pure silver. Traditional one extrusion and multi-gradient adjustable radius one extrusion of AgSnO2 were simulated. As well as extrusion processesing were simulated which the true strain is 4,7.25,10 and 12.5.It can be seen from the silver extrusion simulation processing that the flowing of metal was very similar to the actual situation. The stress and the strain of silver were analyzed.Result of the traditional one extrusion and multi-gradient adjustable radius one extrusion of AgSnO2 extrusion simulation show that:In the course of extrusion,the stress is concentrated on the SnO2 particles mainly, and changes, quickly. And the stress of the Ag matrix is smaller and more stable; The equivalent of plastic strain of the Ag matrixs is greater than SnO2 particles. In the course of extrusion, the SnO2 particles do not deform nearly; With the extrusion ratio greater, the force of extrusion is greater too. Comparing with traditional one extrusion, the margin of the velocity between the surface part of the ingot and the center of the ingot is less in multi-gradient adjustable radius traditional one extrusion. It will help to reduce the phenomenon of shrinking in the end of material. Compared to the same deformation, the force of multi-gradient adjustable radius one extrusion is less than one extrusion.Comparing with the result of AgSnO2 extrusion simulation which the true strain is 4, 7.25,10,12.5, with the true strain increasing, we can find out that those SnO2 particles which reprent as the ring-type,are extruded gradually into the oblate or fibriform shape, through a series of extrusion, uniformly distributed in a Ag matrix, achieving the ideal effect finally.
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