Magnesium is a light-weight (2/3 the density of aluminum) structural metal with the potential to replace Al alloys, Ti alloys, and steels in automotive and aerospace applications. This weight reduction immediately translates to energy efficiency for transportation that help leverage changes to alternative fuel sources. Poor room-temperature ductility—needed for forming—is the main roadblock to widespread adoption of Mg alloys. Ultimately, the problem lies with the hexagonal-closed packed crystal structure of Mg, which produces anisotropic plastic deformation (slip): basal (0001) plane slip requires 100 times less stress than prismatic slip at room temperature. The current approach to overcome this problem is high temperature forming (300ºC) to decreases the anisotropy. We're interested in understanding dislocation motion in Mg and trying to find alloying approaches to reduce the anisotropy. This means strengthening basal slip while simultaneously softening prismatic slip with solutes.

1. “First-principles data for solid-solution strengthening of magnesium: From geometry and chemistry to properties”
   J. A. Yasi, L. G. Hector Jr., and D. R. Trinkle. Acta Mater. (in print) (2010): publication, PDF, doi, preprint
2. “Atomistic study of edge and screw <c+a> dislocations in magnesium”
   T. Nogaret, W. A. Curtin. J. A. Yasi, L. G. Hector Jr., and D. R. Trinkle. Acta Mater. 58, 4332-4343 (2010): publication, PDF, doi
3. “Basal and prism dislocation cores in magnesium: comparison of first-principles and embedded-atom-potential methods predictions”
   J. A. Yasi, T. Nogaret, D. R. Trinkle, Y. Qi, L. G. Hector Jr., and W. A. Curtin. Modelling Simul. Mater. Sci. Eng. 17, 055012 (2009): publication, PDF, doi

This work is in collaboration with Louis G. Hector, Jr. and General Motors, and is funded in part by General Motors and the NSF GOALI program. Computational resources are provided through the NSF TeraGrid program.