TUNGSTEN AND MOLYBDENUM FABRICATED BY LASER POWDER BED FUSION

Additive Manufacturing (AM) is the process that allows the production of complex geometry and lightweight components. According to refractory metals’ high density and their possible applications in the aerospace field, and for biomedical or future nuclear fusion devices, AM could be a good solution. However, selective laser melting of refractory metals as Ta, Mo, and W faces some challenges due to their main properties: high melting point, heat conductivity and susceptibility to cracks. The purpose of this study is to optimize the process parameters in order to produce high-density Tungsten and Molybdenum parts by SLM on an EOS M100 (maximum power of 170 W). Characterization is performed through physical properties measurements and microstructural analysis. Single Scan Tracks (SSTs) are produced on the top surfaces of Tungsten blocks to evaluate the process parameters that give regular-shape and continuous melt-pools. Both analytical and experimental optimization of process parameters were performed. Micro-hardness measurements were done for dense bulk specimens. Finally, a description of susceptibility to cracks of both additively manufactured Molybdenum and Tungsten was performed