|About this Abstract
||Materials Science & Technology 2012
||Recent Advances in Phase Transformations and Structural Evolution in Titanium and its Alloys
||First Principles Study of Beta-Omega Transformations and Interface Structure in Ti-Mo System
||Niraj Gupta, Arun Devaraj, Soumya Nag, Rajarshi Banerjee, Srinivasan Gopalan Srivilliputhur
|On-Site Speaker (Planned)
The beta-omega transformation in titanium is a displacive reconstructive transformation, wherein an anti-parallel shift of atoms by √ 3a/12 in the <111> direction form hexagonal omega structures. Recent characterization of the omega precipitation process in binary Ti-Mo alloys using high-resolution TEM and 3D atom probe tomography show evidence of an extended region of partial, yet continuous collapse between the beta and omega regions extending over distances up to 5 nm. This has been attributed to, the presence and, variation in local Mo concentrations. We propose to use first principle method based on the Vienna Ab initio Simulation Package (VASP) to study the influence of Mo-concentrations on this partial collapse behavior. We will map the energetics of displacement of collapsed planes as a function of molybdenum concentration. We will also investigate the effect Mo-segregation on long-range interfacial displacements using cluster-expansion methods based on VASP.
||Planned: Metallurgical and Materials Transactions