Novel Phase-Field Simulation of Microstructure in Martensitic Materials Available to Purchase

A novel phase-field model of martensite suitable for microstructure simulation is developed here. It is motivated by the hierarchical structure of multirank laminates for establishing the rule of mixtures. As a result, a different choice of field variables, local volume fraction of laminates, is introduced to represent each martensitic variant. It provides an advantage of expressing the energy-well structure of martensitic variants in a unified fashion, instead of choosing the special polynomial expansions of conventional order parameters for a particular transformation. In addition, only two parameters are needed for microsturcture simulation. One is related to the energetic cost due to formation of the interface, and the other is the cost due to the deviation from the ground state energy. The framework is applied to the investigation of optimal microstructures for achieving large actuation strains for dome-shaped and tunnel-shaped microactuators. Finally, the framework is extended to ferroelectric domain simulation. Two cases are discussed: one is for the constrained modeling which restricts polarization remaining on the ground state, and the other is for the unconstrained modeling which allows polarization deviating from the ground state.