Plasticity and Phase Transition of Crystals under Continuous Deformations by Phase Field Crystal Approach

Abstract Despites of some efforts in deformation simulations by the Phase field crystal (PFC) method, simulations of phase transitions and plasticity of crystals under continuous deformations are still lack and some related fundamental issues remain open as well, for example the definition of stresses and the non-zero stresses of unstrained system. In the present work, we propose a deformation simulation method which conforms to the well-established framework of the PFC model. In contrast to traditional deformation simulation methods, our method could naturally mimic melting/freezing, solid-solid phase transition and plasticity of materials under continuous deformations without any additional parameters. Within the frameworks of our method, the stress is well-defined and isothermal-isobaric simulation method is developed. The isothermal-isobaric simulation method enables us to overcome the drawback of previous PFC simulations, for example the nonzero stress of unstrained system. Numerical examples given in present work confirm our conclusions. Particularly, the physical natures of the plasticity are uncovered at the temporal and spatial scale accessible to the PFC method.