Laser-Induced Damage Features and Flow Interference of Coating Materials in Ma=6 Airflows

Aimed at the new application scenario of laser, a test platform was established to study the coating material da-mage features induced by the interaction of the Ma=6 tangential air flow and the continuous laser irradiation. The laser-damaged characteristics of the coating materials in still air and Ma=6 ground-simulated airflows, as well as the corresponding interference flow structures, were presented. Compared with the laser-irradiation ablation phenomenon of the coating materials in still air, the laser-induced damage characteristics of coating materials are significantly different in hypersonic tangential airflows. Under the interaction of hypersonic airflows, the coating materials show a larger damage area when the laser power is low, while the coating materials form deeper ablation pits when the laser power is high. Due to the disturbance from the material ablation, flow patterns similar to those produced by a thermal jet or small protrusion are formed around the ablative structure of coating materials. This phenomenon, in turn, affects the ablation of coating materials, producing a strong coupling phenomenon between hypersonic flow and laser ablation. The results can provide important guidance for engineering applications.