Mechanical and plasma ablation properties of double-interface fibrous ZrB2-SiC ceramics for ultra-high-temperature application

Double-interface fibrous ZrB2-SiC ceramics (DZSw) were prepared by wet-spinning and hot-pressing. The introduction of double-interface layers improves the interface bonding and crack tolerance making the bending strength and toughness of DZSw increased to 607 MPa and 6.3 MPa·m1/2, respectively. After ablation testing in 9.34 MW/m2 plasma flame, DZSw remained intact, with linear and mass ablation rates of -0.3 µm∙s-1 and -0.11 mg∙s-1, respectively. However, single-interface fibrous ZrB2-SiC ceramic (SZSw) produced penetrating cracks, so DZSw presented high ablation resistance than SZSw. The introduction of a dense ZrB2-SiC outer interface layer in DZSw interrupts the three-dimensional connected structure of the porous SiCw interface layer in SZSw and consequently reduces the oxygen diffusion rate of the ceramics. Moreover, the high emissivity and thermal conductivity enable DZSw to serve in the high heat flux ablation environment caused by faster flight speed.