A CrSi2-HfB2-SiC coating providing oxidation and ablation protection over 1973 K for SiC coated C/C composites

•The coating with 15 wt.% Cr can protect C/C 415 h at 1973 K in air.•After ablation for 90 s, the coating has a slight increase in thickness.•After ablation for 90 s, mass ablation rate is only 4.56 × 10−5 g/s.•The self-healing glass layer has good stability.