Effect of doping phase on laser ablation resistance of ZrB₂ ceramic coatings

High temperature resistant ceramics, as high melting point materials, have excellent high-temperature ablation resistance and may meet the needs of future laser protection. In order to understand the laser protection performance of ZrB₂ ceramic coating, a high-power solid-state laser was used as the test light source, and a laser ablation experimental platform as well as laser coupling characteristic measurement system were established. The focus was on conducting laser ablation experiments and coating reflectivity tests on ZrB₂ ceramic coating. The laser ablation resistance of ZrB₂ coatings under different laser parameter conditions, and the influences of doped phases (SiC, MoSi₂) were studied by experiment. The results show that compared to the undoped ZrB₂ coating, the doped ZrB₂ coating shows a significant decrease in laser ablation resistance. The conclusion analysis suggests that the doped phase can improve the oxidation resistance of ZrB₂ coating, but it is not conducive to the high reflection and insulation effects of the oxidation product ZrO₂, resulting in a decrease in the threshold of laser damage resistance. The reflectivity test results of the coating before and after laser damage also confirms that the high reflectivity of ZrO₂ is the key to enhancing the laser damage resistance threshold of ZrB₂ coating. Meanwhile, a temperature calculation model for ZrB₂ ceramic coating under continuous laser ablation was established by using finite element software, and the typical laser ablation threshold parameters of ceramic coatings were simulated based on the criterion of substrate melting.