Silicon carbide whisker reinforced silicon carbide composites by chemical vapor infiltration

摘要

Silicon carbide (SiC) whisker reinforced SiC ceramic matrix composites were prepared by chemical vapor infiltration. Microstructure and mechanical properties of the composites were investigated. The fracture toughness of the composites was improved to 5.65-7.21 MPam~(1/2), and its flexural strength value was between 196 MPa and 305 MPa, depending on the relative density. The pullout of rough whisker, crack deflection and whisker bridging are responsible for the improvement in fracture toughness. The randomly oriented whiskers that paralleled to the crack plane, and the weak bonding strength between whisker and matrix could not have much stress transfer from the matrix, leading to the low flexural strength.