Comparative analysis of low-cycle fatigue behavior of 2D-C_f-PyC/SiC composites in different environments

A carbon fiber-reinforced silicon carbide matrix composite with pyrolytic carbon interface (C_f-PyC/SiC) and a protective coating was prepared by isothermal low pressure chemical vapor infiltration. Low-cycle fatigue behavior of this material system was investigated at high temperatures up to 1800°C in a combustion environment and at room temperature in air, respectively. The combustion environment includes thermal mechanical loading, high temperatures, and oxidizing atmosphere. Low-cycle fatigue tests were conducted at a maximum stress level of 180 MPa but at various temperatures and fatigue cycles. The residual strength variation of fatigue-survived samples was due to different damage mechanisms in different environments.