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Ablation under oxyacetylene torch with heat flux of 4186.8(10%kW/m2 for 20 s was performed to evaluate the ablation resistance of C/C-SiC composites fabricated by chemical vapor infiltration(CVI) combined with liquid silicon infiltration(LSI) process.The results indicated that C/C-SiC composites present a better ablation resistance than C/C composites without doped SiC.The doped SiC and the ablation products SiO_2 derived from it play key roles in ablation process.Bulk quantities of SiO_2 nanowires with diameter of 80 nm-150 nm and length of tens microns were observed on the surface of specimens after ablation.The growth mechanism of the SiO_2 nanowires was interpreted with a developed vapor-liquid-solid(VLS) driven by the temperature gradient.
Ablation under oxyacetylene torch with heat flux of 4186.8 (10% kW / m2 for 20 s was performed to evaluate the ablation resistance of C / C-SiC composites fabricated by chemical vapor infiltration (CVI) combined with liquid silicon infiltration (LSI) process. The results indicated that C / C-SiC composites present a better ablation resistance than C / C composites without doped SiC. The SiC and the ablation products SiO 2 derived from it play key roles in ablation process. Bulk quantities of SiO 2 nanowires with diameter of 80 nm-150 nm and length of tens microns were observed on the surface of specimens after ablation. Growth mechanism of the SiO 2 nanowires was interpreted with vapor-liquid-solid (VLS) driven by the temperature gradient.