Laser assisted powder bed fusion of hypereutectic Al-Si using ultra-short laser pulses at different pulse durations (Conference Presentation)

Laser assisted powder bed fusion of pure Aluminum and hypereutectic Al-Si using ultra-short laser pulses at different pulse lengths is presented. The experiments were carried out with a fiber laser system delivering pulses from 500 fs to 600 ps at a wavelength of 1030 nm and a repetition rate of 20 MHz. Time dependent reflectance measurements indicate that the absorption is increased towards shorter pulse durations. In comparison to longer pulses and cw radiation, powder bed fusion using ultra-short laser pulses lead to uniform structures at lower average powers yielding a homogeneous microstructure that exhibits optimized mechanical properties.