Formation and effects of CuO nanoparticles on Ag/SnO2 electrical contact materials

Abstract

The Ag/SnO2 contact materials modified by the in situ formed CuO nanoparticles were prepared through a self-assembly-precipitation method combined with powder metallurgy. The micro morphology and composition proportion of the Ag-CuO composite powders were investigated. The microstructures and physical properties of the prepared Ag-CuO/SnO2 materials were studied. After arc erosion, the surface morphology and element distributions of the Ag-CuO/SnO2 materials were characterized by Scanning Electron Microscopy (SEM) and Electron Probe Microanalysis (EPMA). The results showed that the CuO nanoparticles smaller than 10 nm were formed on the whole surface of Ag powder. The electrical conductivity of the Ag/SnO2 contact materials was significantly increased with the introduction of CuO, and the hardness, however, was slightly decreased, which could improve the workability. The formation of ultrafine CuO nanoparticles significantly improved the arc dispersion and arc erosion resistance of Ag/SnO2 materials. The aggregation of SnO2 particles in the erosion area was effectively suppressed.