Influence of metal powder cross-contaminations on part quality in Laser Powder Bed Fusion: Copper alloy particles in maraging steel feedstock

Metal powder cross-contaminations are a hindrance in powder-based additive manufacturing (AM). Foreign particles can enter the powder feedstock when two different materials are processed on a single machine - either successively through material changes or simultaneously during multi-material AM. In order to evaluate the criticality of named powder impurities, this study investigates the influence of foreign particle inclusions on part quality during laser powder bed fusion of a material combination commonly processed in multi-material AM: copper alloy CW106C particles in maraging steel 1.2709 feedstock. Different contamination levels are examined regarding metallurgical structure, defect formation, and mechanical strength. It is observed that coppery inclusions are dissolved and do not cause cracks, porosity or other defects below three particle percent. Furthermore, ultimate tensile strength and fracture elongation show a slight negative trend for increasing contamination levels.