Preparation of (BN-SiC)n composite coatings on SiC fibers and tensile properties of monofilament

In order to prepare an ideal interphase of continuous fiber reinforced ceramic composite, three types of (BN-SiC)n composite coatings were deposited on the surface of SiC fibers by chemical vapor deposition (CVD). The microstructure of the (BN-SiC)n coatings was characterized. The monofilament tensile properties of SiC fibers with various (BN-SiC)n coatings were investigated. The results show that the (BN-SiC)n coatings deposited on the SiC fibers are dense and uniform. The tensile strength of SiC fibers monofilament decreases with the increasing coating layers. The SiC fibers with single BN coating have the high monofilament strength retention of about 70% and the maximum elongation of about 2.3%. Compared to the original SiC fiber, the monofilament tensile properties of SiC fibers with (BN-SiC)1 and (BN-SiC)2 composite coatings decrease obviously, and the tensile strength retention rates are 42.1% and 32.3%, respectively. © 2019, Editorial Office of Acta Materiae Compositae Sinica. All right reserved.