Oxidation Behavior of SiC/Al2O3/ZrO2 Multi-layer CoatedCarbon/Carbon Composites at Elevated Temperature

摘要

The oxidation behavior of SiC/Al2O3/ZrO2 multi-layer coating, which prepared on Carbon/Carbon samples with theapplication of plasma-spray and pack cementation processes, was investigated at elevated temperature in air. The multi-layercoating was composed of SiC inner layer, Al2O3 transitional layer, ZrO2 thermal barrier layer and outer sealing layer. And it'smicrostructure and element distribution were measured by scanning electron microscope (SEM), electron probemicroanalyser (EPMA) and energy dispersive spectrometer (EDS), respectively. The practical coating was the same as thedesigning coating structure, and the C, Si, Al, O, Zr elements were changed gradually from inter layer to outer layer. In orderto measure the oxidation resistance of the multi-layer coating, the coated C/C samples were exposed in air at hightemperature up to 1650°C?. At last, it was revealed, through oxidation kinetics analysis, that oxidation of coated sample wascontrolled by oxygen transference through the defects in the multi-layer coating.