HfC nanowire-toughened TaSi2-TaC-SiC-Si multiphase coating for C/C composites against oxidation

To prevent carbon/carbon (C/C) composites from oxidation at high temperature, a HfC nanowire-toughened TaSi2-TaC-SiC-Si multiphase coating was prepared by a two-step technique including chemical vapor deposition (CVD) and pack cementation. The microstructure and oxidation resistance of the coating were investigated. The HfC nanowires can effectively reduce the size of microcracks and avoid the formation of through-thickness microcracks in the multiphase coating. Due to the toughening mechanisms including nanowire pullout and debonding, the cyclic and isothermal oxidation resistance of the coating are both improved.