Process development for laser powder bed fusion of pure copper

This paper describes the development of suitable process parameters to ensure a reproducible, defect-free production of pure copper specimen via Laser Powder Bed Fusion (LPBF) also called Selective Laser Melting (SLM). Therefore, a set of experiments was developed and evaluated in a Design of Experiment (DoE) which finally provide an indication about ideal process parameters for melting pure copper powder at a wavelength of 1064 nm. For the experiments Cu-ETP with a copper purity of more than 99.90 % was processed with a laser power of up to 500 W resulting in a maximum density of 99.82 % and an electrical conductivity of 56.88 MS/m. Besides the development of optimal parameter combinations of laser power, laser speed and hatching distance, focusing the laser beam to a spot diameter of about 35 μm with a fused silica f-theta lens and thus high energy intensities of about 416 kW/mm2 resulted in best materials properties.