Laser Processing of Tungsten Powder with Femtosecond Laser Radiation

Laser irradiation of dispensed tungsten powder layer s with grain sizes smaller than 1 μm was investigated using high-repetition femtosecond lase r systems. Laser processing was performed line by line with repetition rates of 1 MHz and varying parameters such as laser power, processing speed, number of scans and pressure. In addition to the ex p cted material ablation and melting, novel phenomena such as crystallisation, emergence of ripple structures, extensive agglomeration and the formation of nano-wires will be discussed qualitati vely with the help of SEM photographs. Dependence on light pressure, pulse overlap and irradiate energy per unit section will be demonstrated. High-resolution microstructures will be discussed a s a first application of innovative laser microsintering technology using high-repetition femtosecond laser pulses.