Phase-field modelling of transformation pathways and microstructural evolution in multi-principal element alloys

The recently developed refractory multi-principle element alloy (MPEA), AlMo$_{0.5}$NbTa$_{0.5}$TiZr, shows an interesting microstructure with cuboidal precipitates of a disordered phase (${\beta}$, bcc) coherently embedded in ordered (${\beta}'$, B2) matrix, unlike the conventional Ni-based superalloys where (${\gamma}'$, L12) is precipitate and (${\gamma}$, fcc) matrix phase. It becomes critical to understand transformation pathway (PTP) leading this order tailor for specific engineering applications. In study, we first propose possible PTP employ phase-field method simulate microstructural evolution along PTP. We then explore PTPs materials parameters that lead inverted being phase, similar those observed superalloys. find maintain as highly discrete particles these PTPs, volume fraction needs be smaller than elastic stiffness should higher