Microstructure and properties of Ag/SnO2 coatings prepared by cold spraying

Cold spraying was used to fabricate Ag/SnO2 coatings on copper substrate with high energy ball milled Ag/SnO2 composite powders. The cold sprayed coatings were annealed under vacuum at a temperature of 600 °C and 850 °C for 2 h. Vickers microhardness and arc erosion tests were conducted to determine the mechanical properties and arc erosion properties of the coatings. The effect of annealing temperature on the microstructure, microhardness and arc erosion of the coatings was investigated. It was found that cold sprayed Ag/SnO2 coatings exhibited denser microstructure and better coating-substrate interface after annealing at 850 °C. The hardness of Ag/SnO2 coatings was evidently influenced by annealing temperature. The arc erosion test results indicated that the arc erosion properties of cold sprayed Ag/SnO2 coatings can be improved significantly by annealing; the coatings annealed at 850 °C showed the best arc erosion properties.