Overall fabrication of uniform BN interphase on 2.5D-SiC fabric via precursor-derived methods.

Boron nitride (BN) interphase plays a crucial role in silicon carbide fiber-reinforced silicon carbide (SiC f /SiC) composites, because it directly influences the mechanical properties and high-temperature resistance of SiC f /SiC composites. However, fabricating a high-quality BN interphase on SiC fabrics with low cost and high efficiency remains a significant challenge. In this study, a uniform and dense BN interphase was overally prepared on 2.5D-SiC fabric by precursor-derived method. Whether it is the surface fiber or the inner fiber of the 2.5D-SiC fabric, the interphase thickness remains consistent at 550 ± 30 nm. Moreover, the obtained BN exhibits a lower crystallization temperature (approximately 1200 °C). Additionally, it maintains a strong bond with the fabric after high-temperature treatment at 1600 °C in an argon atmosphere and also retains robust adhesion after high-temperature vacuum treatment at 1600 °C. This study not only presents the overall fabrication of a uniform BN interphase on SiC fabric but also provides a novel strategy for preparing interphases on various types of fabrics. • A dense and uniform BN interphase is overall prepared by precursor-derived method for the first time. • A lower crystallization temperature of the BN precursor (∼1200 °C) is exhibited. • The BN interphase thickness of the inner and surface fibers of the fabric is 550 ± 30 nm. • At 1600 oC in Ar atmosphere, the BN interphase effectively inhibits SiC grain growth. [ABSTRACT FROM AUTHOR]