Characterization and Fracture Behavior of ZrC-ZrSi2-Al2O3 Composite Coating with Densely Packed Whiskers Microstructure Prepared by Atmospheric Plasma Spraying

A ZrC-ZrSi2-Al2O3 powder system was designed and used for preparing ZrC composite coating. Tailored microstructures such as densely packed ZrC-ZrSi2 whiskers and nanosized alumina grains were observed in the coating lamellae. The zirconia derived from the oxidation of zirconium carbide and zirconium silicide during the plasma spraying process contributed to the formation of the near-eutectic alumina-zirconia area. The formation mechanism of the composite coating was discussed based on the characterization of the coating lamellae and the as-prepared coating demonstrated promising mechanical properties due to the coordination of whiskers and eutectic microstructure.