399 / 2019-02-28 17:39:47

Dynamic crystal plasticity model for magnesium under shock loading

HCP metals; Shock loading; Crystal plasticity

全体主题 > High Pressure Physics and Materials Science

Magnesium as the hexagonal close-packed (HCP) metals is widely used in aerospace industry due to its excellent mechanical properties. When Mg suffers from the shock loading, there will be numerous plastic deformations to generate. At the microscopic they appear as dislocation slip and deformation twinning. A dynamic crystal plasticity model has been proposed for HCP metals under shock loading in this paper. This model is based on the dislocation slip and describes the micro plastic deformation of material. The volume evolution of materials under shock loading cannot be neglected. The equation of state and crystal plasticity model have been incorporated into the constitute relation to describe the rate of volumetric strain and deviatoric strain of materials. Then the responses of velocity and stress for materials under shock loading can be predicted. The single crystal magnesium exhibits high non-symmetry. Vary deformation slips will be activated for different loading directions and it will lead to the different mechanical responses. The simulations and analyses for different loading directions could help for understanding the generation, growth and reduction mechanisms of the slips in the whole deformation process. Furthermore, the effect of deformation mechanisms on the hardening behavior and failure of materials could be explored. The predictions of model capture the experiments well and demonstrate the application of model.