Temperature-dependent crystal-plasticity model for magnesium: A bottom-up approach

- A temperature dependent crystal plasticity modelling framework is proposed.
- A bottom-up modelling approach is proposed for magnesium.
- Deformation twinning and slip is incorporated in the modelling framework.
- The technique is applicable for HCP metals.

A crystal-plasticity model is developed to account for temperature-dependent mechanical behaviour of magnesium in this paper. The constitutive description of plastic deformation accounts for crystalline slip and twining as well as their interactions. The temperature dependence is incorporated into the constitutive equations for both slip and twin modes based on experimental observations. A bottom-up computational modelling framework is proposed to validate the developed constitutive model. First, the crystal-plasticity model is calibrated with experimental results for plane compression at micro-scale. At meso-scale, a three-dimensional representative element volume was adopted to represent the microstructure of polycrystalline magnesium. In the combination with the proposed constitutive theory, the effects of temperature on mechanical response and evolution of twins and texture in polycrystalline magnesium were predicted. Comprehensive experimental validations at meso-scale were performed to consolidate further the developed crystal-plasticity model incorporating temperature dependence in terms of stress-strain curves, the Hall-Petch relationship and texture evolution. This work provides a useful modelling tool for understanding temperature-dependent behaviour of magnesium, which could be used to improve the formability of this family of materials.