9634927 Leckie This project is to study the fundamental aspects of joints in metal (MMC) and ceramic (CMC) matrix composite structures. The research philosophy emphasizes the understanding of the underlying mechanics and its relationship to microstructure and processing. The research approach is based on the design, manufacturing, characterization and analysis of relatively simple joint geometries which allow the study of individual features of the physical problem and its underlying mechanisms, e.g. the strength of the interfaces defined by the fiber ends and the associated debond process. The MMC research will focus on aluminum alloys reinforced with polycrystalline alumina fibers while the CMC joints will be fabricated by vacuum infiltration of multi-alumina slurries into polycrystalline alumina fiber cloth arranged in layers with prescribed discontinuities. The microstructure and delamination resistance of these joints can be modified by suitable control of the sintering temperature and other manufacturing parameters. The emphasis will be identifying the relevant mechanisms and their relationship to processing via microstructure and defects. ***
