Micromechanics in Mg alloys: Role of hard Al2RE precipitates.

• Effects of hard/soft Al 2 RE phases on damage behaviors of Mg alloys have been uncovered by using a CPFEM model. • Microscale damage mechanisms have been found by DIC tests and Al 2 RE quantifications using TEM and 3D XCT. • Crystal plasticity model based on dislocation density proves crack initiation at Al 2 RE phases. • CPFEM predicts stiffer Al 2 RE having better damage resistance than soft ones matching SEM fracture analysis. The influence of hard Al 2 RE phases (Sc , Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) on the overall and local deformation as well as damage mechanism of Mg alloys has been studied by using a crystal plasticity model based on dislocation density with a brittle damage criterion. Microcracks that lead to swift damage initiation and propagation throughout the matrix have been predicted. It has been found that the hard Al 2 RE with higher elastic modulus enhances the damage resistance of the Mg matrix, which was confirmed by fracture SEM/EDS characterizations and phase-field damage simulation. This discovery provides valuable insights for designing Mg alloys with both high stiffness and enhanced damage resistance. [Display omitted] [ABSTRACT FROM AUTHOR]