2019/12/24 by Swarnava Ghosh, Kaushik Bhattacharya, Ghosh, Swarnava +1
Engineering · Materials Science · #Aluminum Alloy Microstructure Properties #Aluminum Alloys Composites Properties #FOS: Physical sciences #Magnesium Alloys: Properties and Applications #Materials Science (cond-mat.mtrl-sci)
paper · pdf · doi:10.48550/arxiv.1912.11434
openalex publication_date 2019/12/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We use first principles calculations to study the influence of\nthermomechanical loads on the energetics of precipitation in magnesium-aluminum\nalloys. Using Density Functional Theory simulations, we present expressions of\nthe energy of magnesium-aluminum binary solid solutions as a function of\nconcentration, strain and temperature. Additionally, from these calculations,\nwe observe an increase in equilibrium volume (and hence the equilibrium lattice\nconstants) with the increase in concentration of magnesium. We also observe an\nincrease in the cohesive energy of solutions with increase in concentration,\nand also present their dependence on strain. Calculations also show that the\nformation enthalpy of \β phase solutions to be strongly influenced by\nhydrostatic stress, however the formation enthalpy of \α phase solutions\nremain unaffected by hydrostatic stress. We present an expression of the free\nenergy of any magnesium aluminum solid solution, that takes into account the\ncontributions of strain and temperature. We note that these expressions can\nserve as input to process models of magnesium-aluminum alloys. We use these\nexpressions to report the influence of strains and temperature on the\nsolubility limits and equilibrium chemical potential in Mg-Al alloys. Finally,\nwe report the influence of thermomechanical loads on the growth of\nprecipitates, where we observe compressive strains along the c axis promotes\ngrowth, whereas strains along the a and b directions do not influence the\ngrowth of precipitates.\n