Exploration of laser ablation protection for HfC coatings on C/C composites above 2900K

Enhancing the laser ablation resistance of C/C composites is of paramount importance for their prospective application as thermal protection materials, given the rapid advancements in high-energy continuous laser technology. Herein, HfC coating was prepared by chemical vapor deposition (CVD) on the surface of C/C composites to resist the irradiation of high-energy continuous laser. The melting occurred with the formation of oxide products, and these molten phases accumulated at the edge of the ablation pit after laser ablation with two different powers. Furthermore, many cracks were formed around the ablation pit due to the formation of phase transformation stress during ablation. With the increase of laser power, the surface temperature and damage area of the coating increased, and the melting of oxide scale caused by ultra-high temperature was the main reason for the failure of coating. This work could be helpful to provide a theoretical basis for the design and application of laser protective coatings.