Simulation study of effects of Ti content on microstructure evolution and elastic constants of immiscible Mg-Ti alloys during rapid quenching process

Abstract

As for immiscible Mg-Ti alloys, how the microstructures and properties change during rapid quenching, which would finally decide their functions, is of significance. Thus, microstructure evolutions and elastic constants of immiscible Mg100-XTiX (X = 1, 10, 20, 30, 40 and 50) alloys have been studied by molecular dynamics (MD) simulation. The Energy-Temperature (E-T) curves and Cluster Type Index Method (CTIM-2) are adopted to analyze the evolution of microstructures. Results show that the crystallization temperature Tc is enhanced with the increase of Ti content X. As the content X of Ti is at 1 and 10, the main structures in system are predominant fcc (12 0 0 0 12 0) coexisting with minor hcp (12 0 0 0 6 6) clusters, and whose values of E and G are both close to 40GPa and 16GPa, respectively. As X is in the range from 20 to 50, the main structures are bcc (14 6 0 8 0 0) clusters. Their values of E and G are close to 70 GPa and 25 GPa. Especially, the G/B ratio reveals that these alloys are all ductile materials.