High temperature interlaminar tensile strength of a SiCf/SiC ceramic matrix composite determined through diametrical compression testing up to 1200°C

Abstract

The diametrical compression test method was used in this study to determine the high temperature interlaminar tensile strength of a SiC_f/SiC Ceramic Matrix Composite. Two disk geometries are employed (Φ4.5 mm and Φ9 mm) with tests performed up to 1200°C, building upon previous room temperature investigations conducted by the authors [1]. For all tests, disks failed parallel to the loading axis spanning between the upper and lower contact points, ensuring repeatability and reliability even at high temperatures. Digital image correlation was applied to selected tests to measure the full-field strain and observe damage progression to ultimate failure. Weibull distribution was implemented to determine the characteristic strength and distribution, to understand the influence of specimen volume and high temperature oxidation. High temperature results were revealed to have a higher characteristic strength and Weibull modulus owing to the associated oxidation mechanisms, whether the formation of silica rich regions or degradation of the interphase.