Fabrication of tungsten surface microstructures via picosecond laser for enhanced laser-damage resistance

Research on protective measures for aerospace service components spans a broad scope. Infrared (IR) lasers exhibit significant military application potential, underscoring the critical need for effective laser protection. Among available materials, tungsten (W) emerges as the preferred choice due to its high melting point and reflectivity. Herein, a theoretical analysis of the IR laser ablation process of W is conducted. The level-set method is adopted to develop a finite element simulation model, capturing temperature evolution, material removal, and gas dissipation dynamics during ablation. Experimental validation clarifies the formation mechanisms of ablation structures and identified optimal laser parameters for subsequent IR laser damage tests. Next, bases on the two-temperature model, a picosecond laser ablation model of W is developed to simulate the electron-lattice temperature dynamics and material removal. Response surface methodology (RSM) is employed to determine laser parameters that optimize microstructural morphology. Finally, comprehensive performance evaluation tests are performed; the protective enhancements of various microstructural arrays are compared. Circular microstructures with arc-bottom are identified as the optimal configuration. Further parametric optimization reveals that arrays with 110 µm spacing and 40 µm depth achieved superior protective performance.