3D Cf/SiC-ZrC-ZrB2 composites fabricated via sol-gel process combined with reactive melt infiltration

Three-dimensional (3D) C f /SiC-ZrC-ZrB 2 composites were successfully fabricated by sol-gel process combined with reactive melt infiltration (RMI) method. With H 3 BO 3 and PVA as raw materials for gel precursor, a porous C-B 4 C matrix was first introduced into the 3D carbon fiber preform by impregnation of the gel precursor, followed by heat-treatments of pyrolysis and carbothermal processes at 1500   °C in Ar atmosphere . Then molten ZrSi 2 alloys were infiltrated into the 3D C f /C-B 4 C preform to obtain 3D C f /SiC-ZrC-ZrB 2 composites. Based on thermodynamic analysis , the formation mechanism of SiC-ZrC-ZrB 2 matrix was revealed. Oxidation resistance and ablation resistance properties of the fabricated 3D C f /SiC-ZrC-ZrB 2 composites were tested using a muffle furnace and a plasma wind tunnel equipment, respectively. The flexural strength of the as prepared composites and its strength retention after oxidation were evaluated. It is revealed that the 3D C f /SiC-ZrC-ZrB 2 composites showed superior flexural strength , good oxidation resistance and excellent anti-ablation properties.