Cameron Rogers, Brigham Young University
Engineering
The mechanical properties of materials are greatly influenced by their microstructure. Grain boundaries, part of the microstructure, effect mechanical properties and the manufacturing of crystalline solids. Grain boundaries in nickel have been shone to be more mobile at temperatures approaching the melting temperature (Olmsted, Holm, and Foiles, 2009). However, little is know about their behavior at low temperatures, and the notion that mobility decreases with decreasing temperature may be incomplete. Using the molecular dynamic simulator LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator) we are simulating the mobility of 41 Σ3 boundaries in nickel, a face centered cubic (FCC) metal, at various cryogenic temperatures. We have begun to see that these boundaries defy the previously stated notion and move faster with decreasing temperature. Using these molecular simulations we are also investigating the underlying mechanisms for this phenomenon, which could lead to further investigation.