TIME-DEPENDENT MATRIX MULTI-FRACTURE OF SiC/SiC CERAMIC-MATRIX COMPOSITES CONSIDERING INTERFACE OXIDATION

Abstract

In this paper, the time-dependent matrix multi-cracking of SiC/SiC ceramic-matrix composites (CMCs) has been investigated considering the fibre/matrix interface oxidation. The time-dependent interface oxidation length and temperature-dependent fibre/matrix interface shear stress in the oxidation and the de-bonded region, the interface de-bonded energy, the fibre and matrix modulus and the matrix fracture energy are considered in the analysis for the micro stress field, the interface debonding criterion and the critical matrix strain energy model. The effects of the fibre volume fraction, the fibre/matrix interface shear stress, the fibre/matrix interface frictional coefficient, the fibre/matrix interface de-bonded energy and the matrix fracture energy on the matrix multi-cracking density and the interface oxidation ratio of SiC/SiC composite are discussed for the different temperatures and oxidation time. The experimental matrix multi-cracking density and fibre/matrix interface oxidation ratio are predicted for unidirectional and mini SiC/SiC composites at different testing temperatures and oxidation time.

Effect of Interface Properties on the Nonlinear Behaviour of Long-Fibre-Reinforced Unidirectional Ceramic-Matrix Mini-Composites Subjected to Tensile and Fatigue Loading

“…The composite materials interface refers to the area with significant changes in chemical composition between the matrix and the reinforcing phase. The interface properties between the fibre and the matrix play an important role on the mechanical behaviour of fibre-reinforced CMCs [5,6]. The interphase transfers the load between the fibre and the matrix after interface debonding, protects the fibre against an oxidative environment, and deflects the matrix cracking along the interface for the nonlinear behaviour of the CMCs [7,8,9,10,11,12,13].…”