Rapid composition verification of interface composites on large fabric areas

Ceramic matrix composites (CMCs) require submicron coatings on the reinforcing fibers to achieve the desired strength and toughness for application in jet engines. These coatings are a critical component of the CMCs, but current generation evaluation methods like scanning electron microscopy and Auger depth profiling are slow, sample only small areas, and are destructive. Confocal Scanning Raman Microscopy (CSRM) offers substantially increased scanning speeds compared to electron microscopy. We will produce a CSRM system designed for rapid chemical characterization of coatings over large fabric surface areas for CMC applications. We will demonstrate that CSRM is capable of identifying oxidation and other critical defects in this coatings relevant to CMC applications. The Phase I effort will identify the imaging and data processing conditions necessary to apply CSRM to BN and Si3N4 coatings on fiber fabrics and design a prototype CSRM system. In Phase II, we will produce that prototype system, integrate it into our manufacturing environment, and translate the imaging conditions to more rapid resonant scanning techniques expanding the types of defects characterized.