2019/04/15 by Sandeep Sugathan, Sugathan, Sandeep, Saswata Bhattacharya +1 · 1 citation
Engineering · Materials Science · #Aluminum Alloy Microstructure Properties #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Metallic Glasses and Amorphous Alloys #Solidification and crystal growth phenomena
paper · pdf · doi:10.48550/arxiv.1904.07401
openalex publication_date 2019/04/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Most of the commercially important alloys are multicomponent, producing\nmultiphase microstructures as a result of processing. When the coexisting\nphases are elastically coherent, the elastic interactions between these phases\nplay a major role in the development of microstructures. To elucidate the key\neffects of elastic stress on microstructural evolution when more than two\nmisfitting phases are present in the microstructure, we have developed a\nmicroelastic phase-field model in two dimensions to study phase separation in\nternary alloy system. Numerical solutions of a set of coupled Cahn-Hilliard\nequations for the composition fields govern the spatiotemporal evolution of the\nthree-phase microstructure. The model incorporates coherency strain\ninteractions between the phases using Khachaturyan's microelasticity theory. We\nsystematically vary the misfit strains (magnitude and sign) between the phases\nalong with the bulk alloy composition to study their effects on the\nmorphological development of the phases and the resulting phase separation\nkinetics. We also vary the ratio of interfacial energies between the phases to\nunderstand the interplay between elastic and interfacial energies on\nmorphological evolution. The sign and degree of misfit affect strain\npartitioning between the phases during spinodal decomposition, thereby\naffecting their compositional history and morphology. Moreover, strain\npartitioning affects solute partitioning and alters the kinetics of coarsening\nof the phases. The phases associated with higher misfit strain appear coarser\nand exhibit wider size distribution compared to those having lower misfit. When\nthe interfacial energies satisfy complete wetting condition, phase separation\nleads to development of stable core-shell morphology depending on the misfit\nbetween the core (wetted) and the shell (wetting) phases.\n