Thermal shock resistance of in situ formed SiC-BN composites

摘要

SiC-BN ceramic matrix composites (SiC-BN CMCs) were in situ synthesized, using Si3N4, B4C and carbon as reactants. Thermal shock resistance of in situ SiC-BN composites was investigated by measuring strength retention after varying temperature difference (Delta T) up to 1100 degrees C and compared with that of monolithic SiC. Monolithic SiC showed rapidly drop in flexural strength above Delta T of 900 degrees C, while SiC-BN composites showed an increase or negligible reduction in flexural strength till Delta T equal to 1100 degrees C, showing a great improvement of thermal shock resistance. (c) 2007 Elsevier B.V. All rights reserved.