Effect of Plasma Spraying Gas on Microstructure and Properties of 95vol.Al_2O_3-5vol.SiC Nanocomposite Coatings

摘要

Based on the strong inhibition of SiC particles on the grain growth of the Al_2O_3 matrix, a mixture powder of α-Al_2O_3 and SiC was used as feedstock to deposit the nanocomposite coatings by plasma spraying. To determine the effect of plasma spraying gas on microstructure and mechanical properties of Al_2O_3-SiC nanocomposite coatings, primary Ar gas and secondary H_2 gas were chosen, which have an effect on temperature and velocity of the flying powders at the time of impacting on substrate. The X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) were used to characterize the microstructures of these coatings. Surface roughness was measured also.