In-situ W alloys processed via Laser-Based Powder Bed Fusion: new materials for Nuclear Fusion

W-based materials are the most promising candidates for plasma-facing applications since they have high melting temperatures, high thermal conductivity, low activation levels, high sputtering energy threshold, and low tritium retention. However, workability could be problematic because of these materials’ thermo-mechanical characteristics. Indeed, tungsten is hard and brittle, and the use of mechanical tooling systems should be avoided, therefore there are strong design limitations. Laser-Based Powder Bed Fusion (PBF-LB/M) is an additive manufacturing technique specially developed for metals. One of the most interesting perspectives in the nuclear fusion research field is the possibility of using additive manufacturing for developing and realizing components made of refractory metals. Some issues still need to be fixed, like the fact that W undergoes cracking very easily. In this work, the cracking behavior of pure W and in-situ W-based alloys processed via PBF- LB/M was examined. Microstructural characterization followed a process parameters optimization campaign to investigate the effects of the alloying elements introduced in the metal.