Thermal shock behavior of as-sintered and pre-oxidation Zr₂Al₄C₅-20SiC composites

A water-quenching technique was adopted to evaluate the thermal shock behavior of as-sintered and pre-oxidation Zr₂Al₄C₅-20 vol.%SiC composites in an air atmosphere. The strength retention of the two kinds of composites was measured after varying temperature (ΔTc) up to 800 °C. As-sintered Zr₂Al₄C₅-20 vol.%SiC showed rapidly drop in flexural strength above ΔT of 400 °C. However, the pre-oxidation Zr₂Al₄C₅-20 vol.%SiC composite showed a higher retained strength up to 800 °C, and the critical thermal shock temperature difference (ΔTc) is as high as 660 °C. The main reasons for a great improvement of thermal shock resistance (TSR) were also discussed and analyzed.