Room-Temperature Deposition Mechanism, Wear and Oxidation Properties of Vacuum Kinetic Sprayed Silicon Carbide on Metallic Substrate

Silicon carbide (SiC) is considered as a critical material because it has outstanding heat and corrosion resistance, a low thermal expansion coefficient and high thermal impact resistance. This study attempted to manufacture a SiC coating layer using vacuum kinetic spraying process. And the microstructure of vacuum kinetic-sprayed SiC was analyzed with a simulation tool to discuss the shock impact of an individual SiC particle at room temperature. A simulation of deposition confirmed that particle shock pressure could increase up to 27.2GPa, and the particles were predicted to fracture to submicron size after plastic deformation. This matched microstructural observation made with a transmission electron microscope. The coating layer formed a unique microstructure composed of bent lattices, fractured submicron-sized crystallites and amorphous layers. Furthermore, basic properties such as wear and high temperature oxidation were evaluated. It is suggested that vacuum kinetic sprayed silicon carbide layer has a role of the protective layer in the high temperature oxidation atmosphere and abrasive environments.