Preparation and characterization of AgSnO2/Cu contact material by supersonic plasma spraying

The nanostructured AgSnO₂ coating applicable to electrical contact material was prepared in the present study. Ag powders were mixed with 12 wt.% of SnO₂ nanopowders by means of high-energy ball milling, and then were sprayed on a pure copper substrate by supersonic plasma spraying. The phase composition and microstructure of the coating were characterized and the microhardness, bonding strength and electrical property were also measured. Results show that the AgSnO₂ coating presents typical splat-like morphology of thermally sprayed coatings and consists of two different areas: one area is the fine SnO₂ particles homogeneously distributed within the Ag matrix where the SnO₂ particles are near-spherical and less than 100 nm, the other area is the Ag phase. Data from this study have demonstrated the technical feasibility of supersonic plasma spraying for the preparation of AgSnO₂/Cu as a source of this material for electrical contact materials.