Exploration on the application of HfC coating laser ablation protection for C/C composites above 2900 K

Abstract

With the rapid development of high-energy continuous laser technology, improving the laser ablation resistance of C/C composites plays a crucial role in the future application of C/C as thermal protection materials. 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 occured 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.