Numerical Investigation of Secondary Deformation Mechanisms on Plastic Deformation of AZ31 Magnesium Alloy Using Viscoplastic Self-Consistent Model

Abstract

Uniaxial tension and compression of AZ31 magnesium alloy were numerically investigated via the viscoplastic self-consistent (VPSC) model to shed a light on the effect of secondary deformation mechanisms (prismatic <a> slip, pyramidal <c+a> slip, and { 10 1 ¯ 1 } contraction twinning) during plastic deformation. The method adopted in the present study used different combinations of deformation mechanisms in the VPSC modeling. In terms of the pyramidal <c+a> slip, it served as the first candidate for sustaining the extra plastic strain during the plastic deformation. The improvement of activity in the pyramidal <c+a> slip contributed to the increase in the mechanical response and the splitting of pole densities in { 0002 } pole figure during uniaxial tension. As for the prismatic <a> slip, its increasing activity was not only conducive to the improvement of flow stress in mechanical response, but also responsible for the splitting of pole densities in { 0002 } pole figure during uniaxial compression. With respect to the { 10 1 ¯ 1 } contraction twinning, it had a negligible influence on the plastic deformation of AZ31 magnesium alloy in terms of the mechanical response as well as the slip and the twinning activities. However, it is better to include the { 10 1 ¯ 1 } contraction twinning in the VPSC modeling to more accurately predict the texture evolution.

Keywords

• magnesium alloy
• deformation mechanisms
• plastic deformation
• polycrystal plasticity modeling