The Silver Base Graded Material's Preparation And Physics Properties

In this paper, different silver based metal oxide composites and gradient composites are prepared by the powder metallurgy(PM) technique. The composites are used as the electric contact materials under moderate current strength condition. Then Comparing anti-welding, welding resistance and other physical properties of different samples.1. Both Ag/ZnO and Ag/ZnO_w are prepared by the powder metallurgy technique, in which Ag/ZnO_w has excellent switching performances. The experimental results showed that the wettability property of ZnO_w and silver show a superior performance, a little ZnO_w in matrix can obviously protect the silver to make Ag/ZnO_w more wonderful switching performances, in anti-welding, welding resistance and other physical properties.than those of Ag/ZnO.2. The FGM materials prepared via the TP have a excellent gradient distribution and exceptional performance. With the same chemical composition of the contact surface for both FGM and other materials, they significantly differ in the performances of anti-welding, welding resistance and other properties, which makes us possible to fabricate the desired electric contact materials through different gradient constitutions of FGM.3. In the researches of the two kinds of FGMs, the same contact surface for both two gradient materials, or the different contact surface for both same grade materials obviously demonstrated different performances. To be specific, the AgZnO_w contact surface of Ag/SnO₂/ZnO_w has bettert electrical performance than that of contact surface of the two FGMs,such as anti-welding, welding resistance and other properties. The inner metal oxides were discovered on the surface for some couples contact materials among all the electric tested FGMs,the stirring effect of molten silver pool generated by the arc as well as the nonuniform strength applied on the surface give rise to this phenomena, The second metal oxide play an important role on performance of the FGM. As the AgZnO_w contact surface of FGM, the other metal oxide plays an important role performance of the entire FGM. Apparently, the SnO₂ is more beneficial to make Ag/ZnO_w compound electric contact material than the La₂O₃.