Processability of pure Cu by LPBF using a ns-pulsed green fiber laser

Visible wavelength lasers appear a straightforward solution for improved density in LPBF of Cu. However, only few high power continuous wave (CW) green lasers are industrially available. Nanosecond (ns) pulsed green laser sources can be appealing for a wider industrial use, if adapted towards a melting-based process avoiding ablation based shockwaves. This work reports the use of a novel ns-pulsed green fiber laser with 100 W average power and 30 MHz pulse repetition rate for processing pure Cu. The work shows that free-standing samples without excessive powder ejection from the powder bed and densities of 98.1% can be achieved with processing conditions similar to a conventional CW lasers.