THERMAL SHOCK RESISTANCE OF MULLITE AND MULLITE-ZrO_2-SiC-WHISKER COMPOSITES

摘要

The thermal shock resistance of mullite, mullite+30 vol% SiC_w, mullite +24 vol% ZrO_2 and mullite +16vol% ZrO_2 +34 vol% SiC_w composites was determined bywater quench tests. The #DELTA#T_C values were 277deg,381deg, 303deg and 381deg C respectively. The thermal shockresistance parameter R was calculated using experimental datafor thermal expansion, Poisson's ratio, flexural strength andYoung's modulus. The R parameter followed the same trends as#DELTA#T_C. Thus, a significant increase was found forSiC_w additions to mullite, while a small increase was found forZrO_2 additions to mullite. Microstructural studies wereaccomplished on the tested specimens to characterize the nature of the cracking.