MatSE News

First Exact Model for Diffusion in Magnesium Alloys at Illinois

3/8/2017  8:00 am

The movement of atoms in solids controls everything.

“Everything” includes the materials our world functions with — batteries, corrosion, the processing of structural materials like steels, advanced structural alloys, and more.

In order to develop new materials, material engineers need to be able to predict how fast impurity atoms diffuse, or spread, in a crystal over a range of temperatures.

Using new computational techniques developed at Illinois, Ph.D. Student Ravi Agarwal and MatSE Professor Dallas Trinkle constructed the first exact model for diffusion in magnesium alloys. Magnesium is the lightest structural metal, and this model could mean big things for material engineers. Einstein first described the fundamental mechanism of diffusion, but it has only been modeled exactly for a few crystals.

“Computer analysis of the magnesium crystal revealed hidden broken symmetries that impact how different atoms would move in magnesium,” Trinkle said.

Combined with state-of-the-art quantum mechanics calculations, Agarwal and Trinkle were able to predict the diffusion of both common and rare earth metals, which can be used to further many vital, practical applications.

“These new results will allow the creation of new, lightweight structural metals for automotive and aerospace applications,” Trinkle said. “This model is particularly enlightening, as we are able to find broken symmetry in atomic moves that were previously thought to be identical… this method can now be used to predict how atoms diffuse in many other materials.”

The findings of this study were published in Physical Review Letters (PRL) as "Exact Model of Vacancy-Mediated Solute Transport in Magnesium."

Editor’s Notes:

This research was supported by the U.S. Office of Naval Research and by the National Science Foundation.

 For more information:

Contact Ravi Agarwal: ragarwl4@illinois.edu

Contact Dallas Trinkle: dtrinkle@illinois.edu