|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Magnesium Technology 2017
||I-43: Phase Transformations of Long Periodic Stacking Ordered (LPSO) Phases at Finite Temperature in Magnesium-Gadolinium-Aluminum Ternary System
||Hongyeun Kim, Yi Wang, Laszlo Kecskes, Kristopher Darling, Zi-Kui Liu
|On-Site Speaker (Planned)
In this work, Phase Transformations of Long Periodic Stacking Ordered structures (LPSOs) at finite temperature in Mg-Gd-Al ternary system were investigated by first-principles calculations. Here, LPSOs include 10H, 14H, 18R and 24R. We developed stoichiometric LPSO phases that captures L1<SUB>2</SUB> clustering of Gd/Al solute atoms with or without interstitial atom at the center of L1<SUB>2</SUB> cluster. Thermodynamic properties of LPSO were predicted using Debye model with inputs from first-principles calculations. Debye temperatures were estimated based on the Debye-gruneisen parameter calculations since the shear and Young’s modulus of LPSO increased significantly compared to pure magnesium (α-Mg). Based on the theoretically predicted thermodynamic properties, the phase stabilities of each LPSO phases with layers of α-Mg at 0K and finite temperature range are investigated. We captures that the trends of phase transformations between LPSO phases in terms of L1<SUB>2</SUB> cluster building blocks with layers of α-Mg as a function of temperature.