Optimized interfacial evaluation methods of SiCf/SiC composites: fiber push-out, fiber push-in and micropillar compression

Due to the significance of interphases for SiCf/SiC composites, interfacial characterization is an indispensable task and tool for composites manufacturing. In this work, optimized fiber push-out, fiber push-in and micropillar compression were used to measure the interfacial properties and analyze the interfacial debonding process. To accurately acquire the interfacial properties, improve the measurement result reliability and evaluate the method applicability, the detailed test procedures and parameters of different techniques were investigated and reformed. In addition, for the first time, a novel debonding-slipping micropillar compression combined with in- situ observation was designed and applied to separate the debonding and slipping stages and calculate the interfacial debonding energy. The interfacial failure process and energy dissipation mechanism of SiCf/SiC composites were clarified. Coupled with the morphology characterization, the optimized interfacial evaluation methods have provided a further understanding of mechanical response curves and parameters, as well as the debonding failure process of interface, while also providing essential data support for the interphase design of high-performance ceramic matrix composites.