Creep Behavior in Interlaminar Shear of a CVI SiC/SiC Composite at Elevated Temperatures in Air and Steam.

摘要

This research investigated the interlaminar shear performance of a SiC/SiC ceramic matrix composite. The interlaminar shear performance was observed in compression of double notched specimens (DNS) at 1200 deg C in both laboratory air and in steam. Compression to failure tests determined the as- processed interlaminar shear strength and interlaminar shear creep tests were conducted with stresses ranging from -22 MPa to -16 MPa. Primary and secondary creep regimes were observed in all creep tests. The specimens tested in creep at -16 MPa in air achieved run-out, defined as 100 hours at creep stress. The residual strength decreased slightly after 100 h of creep in air at 1200 deg C and decreased significantly after 100 h in steam. The fracture surfaces of all samples were examined in order to determine the failure and environmental degradation mechanisms behind the reduced creep performance of the matrix in steam.