Microstructure, material properties, and macroscopic stress state closely interact in determining the strength and fracture resistance of ductile metals. While a fair understanding of the microstructure-stress interaction on strength, deformation stability and damage has been achieved for common engineering alloys, the same is not true for Mg alloys. The remarkable crystallographic plastic anisotropy, tension-compression asymmetry, and strong texture effects are often referred to as origins of deformation instabilities and damage intolerance in Mg. A fundamental understanding of how the net plastic anisotropy influences the macroscopic load-deformation characteristics and deformation stability under general triaxial loading states will potentially aid the development of high-performance Mg alloys. To that end, a concerted multi-scale computational effort is essential in providing a deeper understanding of the deformation micromechanics of Mg alloys.
In this talk, we present the relations between the loading states (principal and off-axis), microstructure (texture, plastic anisotropy, deformation mechanisms) and macroscopic responses including deformation stability through high-resolution HCP crystal plasticity (HCP-CP) modeling and simulation. We also assess a reduced-order model of Mg plasticity against HCP-CP observations to enable the development of guidelines for damage-tolerant materials design.