Tensile mechanical behavior of SiC fiber bundle reinforced composites with different interfaces

Based on the domestic third generation SiC fiber, the SiC fiber bundle reinforced composites with different interface thicknesses and matrix volume fractions were fabricated by chemical vapor infiltration, and the tensile behavior of the composites was investigated. Meanwhile, the influence of interface thickness and matrix volume fraction on the thermal residual stress of the SiC fiber bundle reinforced composites was analyzed by FEM. The FEM results indicate that the radial and hoop thermal residual stresses are obvious at the interface; the two kind of stresses are decreased with the increasing of the interface thickness and are increased with the increasing of the matrix volume fraction. The tensile tests results show that with the increasing of interface thickness, the tensile strength of the SiC fiber bundle reinforced composites tends to increase, and the fiber pull-out length also is increased correspondingly; but under the same interface thickness condition, a high volume fraction of the matrix will lead to the degradation of the tensile strength and toughness of the composites.