Incorporation of modeling and experimentation to unveil the mechanical behavior, deformation mechanisms, and microstructure evolution of the LA103Z Mg–Li alloy under complex loading conditions

LA103Z is a lightweight Mg-Li alloy combining exceptional strength and ductility for aerospace and defense. However, its complex deformation mechanisms require advanced processing techniques for optimized formability. Therefore, it is crucial to understand its deformation behavior, and microstructure evolution under complex loading conditions to enhance its performance and reliability in structural applications. The LA103Z Mg-Li alloy exhibited low anisotropy under uniaxial loading, on the other hand, showed significant tension-compression asymmetry under ETC loading, with a stress difference of 33.21 MPa, highlighting its sensitivity to complex loading paths. Slip activation varied with external conditions, shifting from {111} planes under uniaxial loading to {011} planes under ETC loading, increasing overall slip activity. The α-Mg phase displayed texture evolution, forming an RD-S texture under uniaxial loading with basal and pyramidal <c+a> slip while shifting to TD-S under ETC loading, with a 153.56% increase in prismatic slip activity. The β-Li phase, initially cube-textured, showed grain rotation along the rolling direction (RD) under uniaxial tension, while under ETC loading, rotation followed the <110> axes, resulting in a more dispersed texture. Finally, the Chaboche nonlinear combined hardening (CNCH) model was developed to characterize the deformation behavior of LA103Z alloy under complex loading conditions. The parameters of the developed CNCH model have been further determined through experimentation and validated through finite element modeling. The developed CNCH model effectively captured the tension-compression asymmetry and nonlinear deformation behavior of the LA103Z Mg-Li alloy, providing a reliable predictive framework for its mechanical response under complex loading conditions.