Influence Of Base Plate Coating On LPBF Of WC-Co

Abstract

While additive manufacturing (AM) is rapidly gaining ground as an established manufacturing process for many industries, understanding and controlling process parameters in order to develop validated process chains remains an area for research and development. A critical parameter that is relevant to laser powder bed fusion (LPBF), the most widely used metal AM technology, is baseplate material selection. This is especially relevant for uncommon build materials such as cemented carbides. In this study, LPBF of WC-Co cemented carbides is investigated, evaluating the influence of baseplate coating on the build. A DIN 1.2343 tool steel baseplate was used for WC-Co LPBF builds, both in the uncoated and coated state. WC-CoCr (1350VM) powder was used to coat the baseplate, while two WC-Co powders with different Co content (17 and 12 wt%, respectively) were used to compare builds of these alloys. The WC-Co powders were characterized to establish their suitability for LPBF. Cuboids were printed, with and without supports, on the coated and uncoated baseplates. Low density builds were built (~88% dense) relating to poor printing parameters. Evaporation of Co is present, yet WC-17Co samples on supports showed little evaporation and good build volume.