A modified synthetic driving force method for molecular dynamics simulation of grain boundary migration

摘要: Abstract The synthetic driving force (SDF) molecular dynamics method, which imposes crystalline orientation-dependent forces for grain boundary (GB) migration, has been considered deficient in many cases. In this work, we revealed the cause of deficiency and proposed a modified method by introducing new technique to distinguish atoms grains GB such that can be imposed properly. This utilizes cross-reference order parameter (CROP) characterize local lattice orientations bicrystal introduces CROP-based definition interface region minimize interference from thermal fluctuations distinguishing atoms. A validation was conducted applying it simulate migration behavior Ni 〈1 0 0〉 Al 〈1 1 2〉 symmetrical tilt GBs, comparison with original method. discrepancies between velocities predicted two methods are found proportional their differences For predicts negative misorientation dependency both pressure threshold initiating movement mobility, agree experimental findings other computations but contradict those using Last, applied evaluate mobility Σ5 under different temperature conditions. results reveal strong at relatively low temperatures suggest should as possible large enough trigger continuous migration.