Arc erosion behaviors of AgSnO2 contact materials prepared with different SnO2 particle sizes.pdfVIP

Trans. Nonferrous Met. Soc. China 26(2016) 783?790 Arc erosion behaviors of AgSnO2 contact materials prepared with different SnO2 particle sizes Miao ZHANG, Xian-hui WANG, Xiao-hong YANG, Jun-tao ZOU, Shu-hua LIANG Shaanxi Key Laboratory of Electrical Materials and Infiltration Technology, Xi’an University of Technology, Xi’an 710048, China Received 30 April 2015; accepted 12 October 2015 Abstract: To clarify the effect of SnO2 particle size on the arc erosion behavior of AgSnO2 contact material, Ag?4%SnO2 (mass fraction) contact materials with different sizes of SnO2 particles were fabricated by powder metallurgy. The microstructure of Ag?4%SnO2 contact materials was characterized, and the relative density, hardness and electrical conductivity were measured. The arc erosion of Ag?4%SnO2 contact materials was tested, the arc duration and mass loss before and after arc erosion were determined, the surface morphologies and compositions of Ag?4%SnO2 contact materials after arc erosion were characterized, and the arc erosion mechanism of AgSnO2 contact materials was discussed. The results show that fine SnO2 particle is beneficial for the improvement of the relative density and hardness, but decreases the electrical conductivity. With the decrease of SnO2 particle size, Ag?4%SnO2 contact material presents shorter arc duration, less mass loss, larger erosion area and shallower arc erosion pits. Key words: AgSnO2 contact materials; SnO2 particle size; arc erosion; electrical conductivity; hardness 1 Introduction The electrical contact materials are widely used in switches, relays, contactors and circuit breakers and their properties directly affect the stability and reliability of electric system [1?3]. Hence, it is required that the contact materials should have excellent electrical and thermal conductivities, erosion resistance, welding resistance and low contact resistance [4?6]. Though AgSnO2 contact material has shown a promising prospect due to its environmental ben