High-Throughput Design of Refractory Multi-Principal Element Alloys

The design of high entropy alloys often focuses on identifying near-equiatomic solid solution alloys; expanding these to include multiphase microstructures offers the opportunity to further enhance and control properties. Designing such multiphase, multi-principal element alloys (MPEAs) requires the ability to efficiently survey compositional space for phases and microstructures of interest using integrated experimental and computational methods. Here, we build on prior studies of the Nb-V-Zr system, which forms a BCC solid solution phase and two Laves phases. Applying a convex hull analysis, we predict the effect of Ti, Ta, and Mo additions on the stability of the BCC phase as a function of temperature and composition. The predicted structures are compared with the microstructures observed in compositional libraries prepared using a high-throughput, laser deposition-based synthesis method. This work provides guidelines for predicting compositional effects on microstructure and properties, which will accelerate the design of MPEAs for high-temperature applications.