Processability of WC-CO powder mixtures using slm additive technology

Abstract

This contribution presents the findings from an experimental study which explored the possibility of processing WC-Co-based powders using selective laser melting (SLM) additive technology. Two commercially available WC-Co powder mixtures were studied. One is intended for thermally sprayed coatings and the other for isostatic pressing applications. Both were analysed using optical and scanning electron microscopy and then processed in an additive manufacturing (AM) machine. Process parameters were proposed on the basis of a literature search and metallographic characterization of the mixtures. Metallography was also employed for examining the prototype specimens. The mixtures were found to differ in morphology, technological properties and phase composition, which was also manifested during their processing. The powder mixture for thermally sprayed coatings proved completely inadequate for AM due to undesirable grain morphologies and phase composition. The powder mixture for isostatic pressing was found to be more suitable. Nevertheless, all the builds were highly porous which had an adverse impact on the product properties.