Influence of the beam power on the density of pure copper samples in PBF-EB/M using a spot melting strategy

Pure copper is well-suited for the powder bed fusion of metals using an electron beam. The main reason is that the high reflectivity of the copper powder is non-critical for the energy coupling of the electron beam compared to the laser beam in the powder bed fusion of metals using a laser beam. However, due to the high thermal conductivity of pure copper, it is necessary to adjust the heat energy input to achieve sufficient melting while avoiding process defects from local overheating. To achieve this, a spot melting strategy is applied in this study to manufacture pure copper samples with a homogeneous heat input and thermally independent melt pools. In an experimental study, this paper investigates the influence of applied beam power on the density of pure copper samples at constant volume energy density. This paper shows that optimal beam power can reduce the dwell time and thus the time required for heat input. This also shortens the time required for heat dissipation. Therefore, despite copper’s high thermal conductivity, denser samples with lower volume energy density could be produced because heat dissipation was reduced.