Tensile Behaviors and Matrix Cracking Mechanism of C/SiCN Composite Prepared by Precursor Infiltration Pyrolysis Method

Significant matrix cracks and residual pores may form within ceramic matrix composite which was prepared by polymer infiltration and pyrolysis (PIP) method.Explore the matrix cracking mechanism and the crack evolution behavior would benefit the design and performance optimization of the composite.A spinning PIP process in vacuum was adopted to prepare mini C/SiCN composite without weak interphase.The tensile properties and the matrix crack evolution phenomena were analyzed.The influences of PIP cycles and heat-treatment temperatures were discussed.Results showed that the compositions are essentially the same for the samples heat-treated at 1000-1400 ℃.While the heat-treatment temperature rises to 1600 ℃, the precursor-derived SiCN matrix decomposes, with the carbon content decreased and SiC content increased significantly.As PIP cycles increased from 1 to 4, the average tensile