Multiscale Modeling of Zn-Cr-S Alloy: Integrating DFT, CALPHAD, and Molecular Dynamics for Thermomechanical Property Prediction

The thermomechanical performance of alloys is a decisive factor in their application to structural, aerospace, and energy systems. This study provides a thermomechanical review of Zn-Cr alloy behavior by integrating computational thermodynamics (Thermo-Calc) with atomistic simulations (LAMMPS) to establish a multiscale understanding of its stability and deformation mechanisms. Thermo-Calc was employed to generate equilibrium phase diagrams, Gibbs free energy variations, and solubility limits across a wide temperature spectrum, allowing the identification of critical transformation points and phase stability trends. These thermodynamic insights provide a baseline for predicting alloy strengthening and thermal stability when chromium is introduced into the zinc matrix. In parallel, molecular dynamics simulations using LAMMPS were conducted to probe atomic-scale interactions, including stress–strain responses, defect evolution, and dislocation dynamics under combined thermal and mechanical loading. The simulations further revealed the influence of chromium content on diffusion kinetics, grain boundary cohesion, and resistance to thermal softening, offering valuable mechanistic insights into strengthening behavior. By correlating macroscopic thermodynamic predictions with atomistic deformation pathways, this research highlights the synergistic role of multiscale modeling in advancing alloy design. The Zn-Cr alloy system emerges as a strong candidate for structural applications due to its balance of phase stability and mechanical robustness, particularly under elevated temperatures. Beyond the Zn-Cr system, the methodological framework demonstrated here illustrates the power of coupling CALPHAD-based thermodynamics with molecular simulations in alloy development, enabling predictive insights that reduce reliance on experimental trial-and-error. Overall, this paper here not only consolidates knowledge of Zn-Cr alloy thermomechanical behavior but also positions computationally guided approaches as indispensable tools in the pursuit of next generation materials for high performance additive manufacturing applications.