The effects of annealing treatment on microstructure and contact resistance properties of cold sprayed Ag-SnO2 coating

In this paper, the effects of annealing treatment on microstructure and contact resistance properties of Ag-SnO2 coating prepared by cold spraying was investigated. The microstructure of cold sprayed Ag-SnO2 coating and its arc erosion morphology were investigated by Scanning Electron Microscopy (SEM). The average surface roughness Sa and surface profiles of Ag-SnO2 coating samples after arc erosion testing were also researched by Scanning Laser Microscope (SLM) 3D surface technique. It can be found that the surface morphology of arc eroded Ag-SnO2 coating annealed at 850 °C was stable and uniform compared with that of original coating samples. Moreover, Ag-SnO2 coatings annealed at 850 °C exhibits excellent contact resistance performance as applied in coatings stabilize in 3.5 mΩ. The present experimental results indicated that annealing treatment is the main factor that effects the microstructure and contact resistance properties of cold sprayed Ag-SnO2 coating and the contact resistance properties of cold sprayed Ag-SnO2 coating annealed at 850 °C exhibited low and stable value.