Processing, characterization, and mechanical properties of beta silicon nitride whisker/silicon nitride matrix composites
Ceramic matrix composites, consisting of $\beta$-$\rm Si\sb3N\sb4$ whisker reinforced polycrystalline $\rm Si\sb3N\sb4$, were fabricated with controlled whisker/matrix interfaces, characterized on the microstructural level, and evaluated for mechanical reliability. As-received and coated $\beta$-$\rm Si\sb3N\sb4$ whiskers were used to reinforce the $\rm Si\sb3N\sb4$ matrices. Whisker coatings were achieved by low pressure chemical vapor deposition of BN. As-received and coated whiskers and as-received powders were characterized using XRD, XPS, SEM, and TEM techniques. Composite microstructures, including the whisker/matrix interfacial zones, were characterized by SEM and TEM. Mechanical properties of the composites, primarily fracture strength and fracture toughness, were measured and compared to those of the unreinforced matrices.
Applied Mechanics, Engineering, Materials Science
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign