High performance SiC fiber-reinforced celsian matrix composites with BN/ C/SiNx/C interface

Strong, tough, and almost fully dense unidirectional SiCf/BSAS composites were obtained through the slurry infiltration and hot-pressing process. The 0.75BaO-0.25SrO-A12O3-2SiO2 mixed precursor synthesized by solid state reaction from metal oxides was utilized as the matrix slurry. SiC fibers with BN/C/SiNx/C coating served as reinforcements. During hot pressing, the monoclinic celsian phase in the matrix was produced in situ. The composite exhibited graceful failure in three-point bend tests at room temperature. The flexural strength and strain reached 315.37 MPa and 0.44 %, respectively. With the help of the BN/C/Si3N4/C coating, the SiC fibers occur debonding and pull-out, exhibiting outside debonding features. After annealing in O2 at 850 degrees C for 10 h, the strength retention rate of the composites was 95.41 %, showing excellent stability for in thermal structural components.