INTERACTION OF PURE TUNGSTEN POWDER WITH PROCESSING CONDITIONS IN SELECTIVE LASER MELTING

摘要

In this study we consider the role of the pure tungsten powder interaction with processing conditions within Selective Laser Melting (SLM). Tungsten powder (sub 45μm) was subjected to investigations which involved the creation of a process map through single track and single layer hatching studies. The effects of laser power, scanning speed and hatch spacing were studied using the process map parameters. Light optical microscope, scanning electron microscope and X-Ray diffraction techniques were used to analyse the results. The studies showed that for the given laser energy density, the temperature and the volume of the molten powder was higher at lower scanning speeds. The results also showed distinguished grain structures between the x-y horizontal build plane and the z-y vertical build direction. The SLM process was successfully used to fabricate highly dense tungsten of up to 98% density.