Modifying effects of in-situ grown LaB6 on composition, microstructure and ablation property of C/C-SiC-ZrC composites

LaB6 powders with uniform distribution were successfully in-situ grown in the substrate of C/C felt. ZrC and SiC were subsequently introduced to fabricate four kinds of LaB6 modified C/C-SiC-ZrC composites. The ablation property of composites was codetermined by fiber structure and ablation-resistant ability of oxide scale, which were all lied on the relative fraction of in-situ growth LaB6. Doping with 22.12 wt%LaB6, the composites showed decent mechanical and the best ablation properties among all fabricated composites. After plasma ablation for 120 s, the mass and linear ablation rates of composites were 1.541 mg/s and 1.924 mu m/s, respectively.