High-power ultrashort pulse laser machining of tungsten carbide

Abstract This paper presents the results of an investigation, performed using a 300 W picosecond laser, for deep (~4 mm) machining of tungsten carbide. The influence of picosecond laser parameters on the precision and quality were studied and discussed. Laser pulse frequency and scanning speed have minimal effect on ablation rate at high power levels. The surface roughness of the ablated area increases with the ablation depth. Optimal fluence of 6 J/cm2 results in an energy specific ablation volume (ESAV) of 2.2E-3 mm3/J and surface roughness Sa of 2.2µm. At optimal conditions, no thermal defects were observed, even at a high average power of 300 W. The material removal rate (MRR, mm3/min) seems to be proportional to the average power of the laser, and a MRR of around 45 mm3 per minute can be achieved at a 300 W power level.