Evolution and characterization of cyclic thermal shock-induced thermomechanical damage in oxide/oxide ceramics matrix composites

摘要

Thermal shock is a typical loading case for high temperature components in turbines. The ceramic matrix composites become attractive for their high temperature behavior. However, their low heat conductivity makes thermal shock damage a typical damage mechanism for the turbine application. In the present paper, microstructural evolutions of the oxide/oxide ceramic matrix composite under thermal shock are studied experimentally. The mechanical behavior is related to the thermal shock temperature and cycles. The thermo-mechanical damage is characterized by degradation of the macroscopic elastic modulus. A thermal shock damage model is introduced based on the continuum damage mechanics principle, which can describe monotonic as well as cyclic thermal shock damage processes.