ZrB_2-SiC Oxidation Protective Coating on C/C Composites Prepared by Vapor Silicon Infiltration Process

摘要

ZrB_2-SiC coating on C/C composites was prepared through vapor silicon infiltration process. The coated C/C composites showed excellent oxidation performance at 1500℃. Isothermal oxidation results showed that there was weight gain accompanied in the whole oxidation process and no evidence of oxidation of C/C composite substrate was observed. The thickness of coating increased from 120 μm to about 200 μm after oxidizing at 1500℃. Three distinct layers could be observed in the coating, namely, outer SiO_2-rich layer, middle ZrB_2-rich layer, and inner SiC-rich layer. ZrB_2 particles were coarsened after oxidation.