Mechanical and interfacial properties of SiC fiber‐reinforced SiC composites

Abstract

The interfacial strength of SiC/SiC composites fabricated by hot‐pressing (HP) and CVI method was measured by push‐in test, and the relation between interfacial and mechanical properties of the composites was investigated. Maximum strength and fracture energy of the CVI‐composite was higher than those of the HP‐composite due to lower interfacial shear sliding strength and higher fiber strength. The composite hot‐pressed at 1750°C had a higher interfacial shear sliding strength, lower fiber strength, shorter fiber pull‐out length and a smaller single fiber pull‐out energy, resulting in low maximum strength and fracture energy. The composite hot‐pressed at 1650°C showed a lower maximum strength and higher fracture energy in spite of a lower interfacial shear sliding strength, higher fiber strength, larger fiber pull‐out length and a single fiber pull‐out energy. In this case, the delamination between fiber and the matrix occurs easily.