Mechanical behavior of SiCf reinforced SiC composites with fiber coating - Stress alleviation in SiC fiber by soft coating layer

Abstract

The present research attempts to analyze and evaluate the mechanical behavior of SiCf in SiCf/SiC composites with and without soft coatings. The effects of soft fiber coating in the alleviation of indentation or flexural stress in the layered structure are investigated. Boron nitride and/or pyrocarbon as soft coating layer on SiC fiber are selected for the structure. Modeling is performed by changing the type of fiber, the type of soft layer, and layered stacking sequence of the soft layer. Finite element method (FEM) analyses are conducted to evaluate stress distributions under indentation or flexure loadings by displacement loading. Experimentally, the fiber coatings are conducted in the SiC fiber reinforced SiC composites. It was found that BN and/or pyrocarbon coating on the fiber alleviate the stress under the contact or flexure loading, which indicates that the appropriate design by soft layer on the fiber can reduce the maximum stress. © 2009 The Ceramic Society of Japan. All rights reserved.