Improved mechanical and microwave absorption properties of SiC fiber/mullite matrix composite using hybrid SiC/Ti3SiC2 fillers

SiC fiber reinforced mullite matrix (SiCj/Mu) composites were prepared via an infiltration and sintering process using SiC and Ti3SiC2 as inert fillers. The effects of SiC and Ti3SiC2 fillers on microstructure, mechanical, dielectric and microwave absorption properties of the composites were studied. The composite with 15 wt% SiC filler obtained a flexural strength of 300 MPa. The complex permittivity of the composite was enhanced from 12.3-j22.1 to 14.2 -j39.7 at 10 GHz when the Ti(3)SiC(2 )content increased from 10 wt% to 30 wt%. By adding 15 wt% SiC and 10 wt% Ti3SiC2 in the matrix, both mechanical and microwave absorption properties of the SiC(f/)Mu composites were significantly improved. A flexural strength of 292 MPa and a failure displacement of 0.47 mm were obtained for the composite with hybrid SiC/Ti3SiC2 fillers. The composite with a thickness of 2.9 mm obtained an effective absorption bandwidth of 3.3 GHz (from 9 to 12.3 GHz), with a minimum reflection loss of -53 dB at 8.64 GHz. Results indicated that the SiCf/Mu composite with hybrid SiC/Ti3SiC2 fillers was one of the excellent structural-functional candidates for military application. (C) 2019 Elsevier B.V. All rights reserved.