Fabrication of SiCf/SiC-mullite composite with improved pretreatment condition via precursor infiltration-sintering combined with infiltration-pyrolysis process

Abstract

Abstract SiC fiber/ceramic matrix composite has potential applications in military and civil fields due to their excellent microwave absorption performances, light weight and oxidation resistance. In this work, the SiCf/SiC-mullite composite with improved pretreatment condition was fabricated via precursor infiltration-sintering combined with infiltration-pyrolysis process for achieving excellent mechanical and microwave absorption performances. Results indicated that different dehydrations of matrix precursor influenced ultimate mechanical properties of the composites. At the same time, SiC derived from polycarbosilane had significantly improved several properties of the composite. The flexural strength and failure displacement reached 266 MPa and 0.46 mm, respectively. The high loss tangent was related with the interfacial polarization. In addition, a prominent reflection loss value of −45 dB was observed at 9 GHz. What's more, the maximum absorption bandwidth reached 2.9 GHz (from 8.2 to 11.1 GHz). The SiCf/SiC-mullite composite with improved pretreatment condition is expected to be an excellent structural-functional material.