High-throughput refractory alloy design for additive manufacturing

Commercial implementation of higher strength refractory alloys has largely been hindered by their poor fabricability. Additive manufacturing (AM) may provide more opportunities to fabricate stronger refractory alloys, but discovering alloys that are amenable to the printing process without cracking remains a challenge. Here, utilizing a high-throughput methodology, the tendency for cracking during laser melting was evaluated in 595 alloys in the Nb-Zr-W alloy family. In this approach, discontinuous compositional gradients are fabricated using spark plasma sintering, streamlining the subsequent laser spot melting and automated correlative characterization efforts. By assessing compositional trends in crack severity, promising alloy design strategies to mitigate interstitial embrittlement, solid-state cracking, and solidification cracking emerge. The results presented here establish how AM can broaden the refractory alloy design space, and provide a suitable compositional library for the development of predictive criteria for cracking.