A first-principles study of elastic and diffusion properties of Magnesium based alloys

Open Access
Author:
Ganeshan, Swetha
Graduate Program:
Materials Science and Engineering
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
October 15, 2010
Committee Members:
  • Dr Zi Kui Liu, Committee Chair
  • Jorge Osvaldo Sofo, Committee Member
  • Digby D Macdonald, Committee Member
  • Long Qing Chen, Committee Member
Keywords:
  • diffusion coefficients
  • First-principles
  • elastic properties
  • Magnesium
Abstract:
In this thesis, the influence of alloying elements on the elastic and diffusion properties of Magnesium (Mg) has been studied based on first-principles density functional theory. The alloying elements include Al, As, Ba, Cd, Ca, Cu, Ga, Ge, K, Li, Ni, Pb, Si, Sn, Y, and Zn for elastic properties and Al, Ca, Sn, Zn for diffusion properties. The stress-strain method has been used to predict the elastic constants of the Mg based alloys studied herein.The methodology involved in calculating the diffusion coefficients is based on Eyring’s reaction rate theory. Vacancy-mediated volume diffusion has been assumed for all the calculations. This work is aimed at providing a better understanding of the mechanical compatibility between different alloying elements in Mg, and the influence of these elements on Mg, in terms of its elastic and diffusion properties. The methodology, results and analysis presented herein can act as a bench mark for not only future first-principles calculations of elastic and diffusion properties in Mg based alloys but also for other hexagonal closed packed systems.