We can examining dislocation/solute interactions to understand the problem of Mg solutes pinning dislocations in aluminum. The pinning by a “Cottrell atmosphere” of solutes is governed by the attraction of Mg solutes to the tensile strain field of an edge dislocation. Accurate density-functional calculations provide interaction energies all the way to the core of the dislocation. The accurate modeling of Al dislocation/Mg solute interaction is important for dynamic-strain aging: mechanical behavior that produces shear-bands (the Portevin-Le Chatlier, or PLC, effect)—which limits the formability of Al alloys.

1. “Prediction of dislocation cores in aluminum from density functional theory”
   C. Woodward, D. R. Trinkle, L. G. Hector, and D. L. Olmsted. Phys. Rev. Lett. 100, 045507 (2008): publication, PDF, doi

This work was in collaboration with Louis G. Hector, Jr. and General Motors and Christopher Woodward at AFRL.