Abstract:The preparation method and arc erosion characteristics of the AgNi and AgSnO2 contacts materials which was fabricated by high-energy ball milling, hot pressing and sintering were studed. The powder morphology and microstructure of contact were analyzed by X-ray Diffraction (XRD), Scan Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The results shows that the grain size of composite powder has been fined, that the particle size of second phase was about 40 nm after high energy ball milling and the particles are dispersed in the Ag matrix in inlaying and welding, in witch the second phase aggregatin in the matrix and deposition on the grain bourdary that was caused by orthodox method has been abated. After hot pressing and annealing, there was not obviously growth of second phase and the particle size was about 50 nm. It was also found that the Ag film distributed on the grain boundary was retained in both contacts, which was propitious to the improvement of conductance capability. Compared with the commercial contacts, there was not obviously melting pool and splash of fused mass on the nanocomposite contact surface, which indicated that the arc on the contact surface was dispersed and the material was possessed of less are erosion in the arcing process.