Ablation Performances of Multi―phased C/C―ZrC―SiC Ultra―high Temperature Composites

The 2D C/C―ZrC―SiC composites were prepared through precursor infiltration and pyrolysis (PIP) process using a hybrid precursor contained polycarbosilane and organic zirconium―contained polymeric precursor. The microstructures and ablation behaviors of the prepared composites were studied. The composition and microstructure of the ablated samples were characterized by XRD and SEM, respectively. The results show that the mass ablation rate and linear ablation rate of the composites generally firstly decrease and then increase with the increasing of ZrC contents. The sample with 17.45vol% ZrC has optimum anti―ablation property. After ablation at 2200 for 300s via the plasma torch heating technique, the mass loss and linear recession rate is as low as 1.77mg/s and 0.55μm/s, respectively. It is found that during ultra―high temperature stage, the matrix of ZrC and SiC are oxidized into ZrO2 and SiO2, which form a kind of viscous binary glassy mixture. The mixture could effectively cover the ablation surface and therefore promote its anti―ablation property.