Ceramic Matrix Composites (CMCs) are being developed for use in extreme operating conditions. Specifically, there is interest to replace superalloys with Silicon-Carbide/Silicon-Carbide (SiC/SiC) CMCs in the hot section of gas turbine engines because of their lower densities, high temperature performance, and oxidation resistance. Due to the high temperature processing conditions of SiC/SiC CMCs, there are thermal residual stresses inherent to the material. This study focused on using micro-Raman Spectroscopy on as manufactured SiC/SiC CMCs to measure and investigate the residual stresses within a fiber and the matrix material. Following the silicon Raman active mode at 520 cm-1 and the SiC Raman active mode around 790 cm-1 within the composite, residual stresses within the matrix and the reinforcing fibers could be investigated with a spatial resolution of 1 micron. Understanding the residual stress will enable better understanding of behavior and life performance in application environments.
Kollins, K. (2016). Micro-Raman Investigation of Residual Stresses in SiC/SiC Composites. Wright State University, Dayton, Ohio.