Phase-field modelling of microstructure evolution in displacive transformations

Displacive transformations, like deformation twinning or martensitic transformation, are associated with microstructure evolution, which involves nucleation, propagation and annihilation of interfaces. For instance, the functional properties of shape-memory alloys (SMAs), notably the shape-memory effect and pseudoelasticity, result from the reversible martensitic phase transformation which, at the micro-scale, proceeds through formation and evolution of complex martensitic microstructures. Spatially-resolved modelling of the corresponding phenomena can be efficiently carried out using the diffuse-interface approach, and specifically using the phase-field method. In this talk, our recent related results will be summarized. Size effects, rate-independent dissipation, and microstructure evolution in pseudoelastic SMAs during nano-indentation will be discussed. A finite-strain phase-field model of deformation twinning coupled with crystal plasticity will also be discussed, including a new look at the kinematics of twinning.