Recent advances in interphase engineering for improved behavior of SiCf/SiC composites

Continuous silicon carbide fibers (SiCf) reinforced SiC ceramic matrix composites (SiCf/SiC CMCs) are promising thermostructural materials with a broad range of high-end technology applications. For the excellent performance of SiCf/SiC CMCs, the interphase plays a crucial role in tailoring the overall mechanical properties and service lifetime of SiCf/SiC CMCs. During the past decades, tremendous effort has been made to develop better interphase materials and deepen the understanding of their functions and mechanisms. In this paper, an overview of the latest advancements in a variety of interfacial coatings, including pyrolytic carbon, boron nitride, newly developed layered candidates, porous oxides and multilayers, is provided. Emphasis is placed on the engineering of constituents, microstructure and interphase thickness, as well as their effects on the mechanical properties and stability of SiCf/SiC CMCs. Moreover, the challenges and future opportunities to achieve the desired behavior of SiCf/SiC CMCs by interphase engineering are discussed.