Anomaly Detection and Microstructure Characterization in Fiber Reinforced Ceramic Matrix Composites

ANOMALY DETECTION AND MICROSTRUCTURE CHARACTERIZATION IN FIBER REINFORCED CERAMIC MATRIX COMPOSITES Name: Bricker, Stephen E. University of Dayton Advisor: Dr. Russell Hardie Ceramic matrix composites (CMCs) have the potential to replace current superalloys being used in hot components of jet engines. CMCs with continuous fiber reinforcement exhibit significant strength retention beyond temperatures at which Nickel based superalloys approach their melting temperature (900◦ C). While ceramics typically exhibit brittle failure modes making them unsuitable for use in dynamic systems, fiber reinforcement increases fracture toughness, crack growth resistance and strength. Differences in weave type, processing technique, and chemical makeup, however, result in a broad range of material microstructures each with a high degree of variability. Little is known about how the variation and imperfections within the microstructure affect the material properties. It is theorized that stress concentrations exist at certain abnormal microstructural configurations, resulting in either crack nucleation or propagation. Due to the amount of data available and the amount of variation in the microstructure, it is impractical to hope to discover the relationship between microstructural organization and cracking simply by observation. Instead, it is thought that the areas of greatest importance are those that do not adhere to the typical behavior