Elevated-temperature stress rupture in interlaminar shear of a Hi-Nic SiC/SiC ceramic matrix composite

Assessments of stress rupture in a gas-turbine grade, melt-infiltrated Hi-NicalonTM SiC continuous fiber-reinforced SiC ceramic matrix composite (CMC) were made in interlaminar shear at 1316 °C in air. The composite exhibited appreciable life limiting behavior with a life susceptibility parameter of ns = 22–24, estimated based on a proposed phenomenological life prediction model together with experimental data. The phenomenological life model was in good agreement in prediction between the stress rupture and the constant stress-rate data, validating its appropriateness in describing the life limiting phenomenon of the CMC coupons subjected to interlaminar shear. The results of this work also indicated that the governing mechanism(s) associated with failure in interlaminar shear would have remained almost unchanged, regardless of the type of loading configurations, either in stress rupture or in constant stress rate.