A phase-field approach to solid–solid phase transformations via intermediate interfacial phases under stress tensor

摘要: Abstract A thermodynamically consistent phase-field (PF) theory for phase transformations (PTs) between three different phases is developed with emphases on the effect of a stress tensor and interface interactions. The equilibrium stability conditions homogeneous are derived thermodynamic potential which satisfies all these introduced using polar order parameters. Propagation solid–solid (SS) containing nanometer-sized intermediate disordered interfacial (IP) particularly an melt (IM) studied HMX energetic material PF model. scale effects (the ratio widths SS to solid-melt (SM) interfaces, k δ ), energy SM interfaces ( E temperature formation IM investigated. An interaction two via IM, plays key role in defining well-posed problem mesh-independent solution, captured special gradient term. influence elastic retainment its structure, hundreds degrees below melting temperature, Elastic promotes barrierless terms increasing degree disordering, velocity, width but it surprisingly increases nucleation IM. effect, however, drastic reduction (by more than magnitude) critical nucleus within interface, caused by energy. model applicable general case PT can be applied (adjusted) other physical phenomena, such as premelting/disordering at grain boundaries, martensitic PTs, surface-induced premelting developing diagrams.