Oxidation Resistance of ZrB_2-SiC-WSi_2 Coating Prepared by Vacuum Plasma Spraying

摘要

ZrB_2-SiC-WSi2 (labeled as ZSW) coating and ZrB_2-SiC (labeled as ZS) coating were fabricated by vacuum plasma spray technique. The microstructure and composition of as-sprayed coating were detected through X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray energy dispersive spectrometry (EDS). Oxidation behaviors and microstructure evolution of these coatings were evaluated at 1500 °C in air and compared with ZrB_2-SiC coating. The results showed that the addition of WSi_2 improved the oxidation resistance of the ZrB_2-SiC coating. There was more liquid formed on the ZSW coating surface. Some bubbles were also observed on the coating surface, which might be resulted from gas formation. It can be concluded that the amount of WSi_2 had great influence on its function in ZrB_2-SiC system.