Ablation behavior and mechanism of Al3BC/Al composite coating irradiated by high energy laser

In this work, a new type of laser protective material, i.e. Al₃BC/Al composite coating is proposed. The Al₃BC/Al composite powders used for the spraying process has been firstly fabricated by a sintering process and the submicron Al₃BC particles are in-situ synthesized. The Al₃BC/Al composite coatings were then prepared using a high-velocity air fuel (HVAF) spraying process, and the optimum fabrication parameters were determined by an orthogonal experiment. The Al₃BC/Al composite coatings fabricated by the optimum parameters are dense, with submicron Al₃BC particles uniformly dispersed. The laser ablation behavior of the Al₃BC/Al coating was also investigated in this work. The Al₃BC/Al composite coating endured 10 s before failure, which is twice the laser ablation resistance time of pure Al coating (failure at 5 s), revealing the excellent laser protection performance of the composite coating. By investigating the microstructure evolution of the coating during the laser irradiation, the ablation mechanisms of the coating are revealed. Both the good thermal stability of Al₃BC particles and a further endothermic decomposition reaction contribute to the excellent laser ablation resistance of Al₃BC/Al composite coating. This work will provide a new idea and theoretical guidance for the design of novel laser protective coating material.