Complexity of Grain Boundary Motion: Insights from Molecular Dynamics

The microstructure of materials has a profound influence on the full range of materials properties including strength, electrical resistance, and corrosion to name but a few. The understanding and modeling of the evolution of the grain microstructure during processing and use requires knowledge of the mobility of grain boundaries. Molecular dynamics simulations of grain boundary structure, energy and mobility have been performed over the years as a function of the five crystallographic degrees of freedom as well as temperature. Recent results on the mobility of grain boundaries as a function of temperature have revealed unexpected complexity and challenge some of the long-standing pervasive assumptions about grain boundary motion. These results will be overviewed and future directions in grain boundary research will be described.

Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.