| Abstract Scope |
Isolated cylindrical grain boundaries in embedded bicrystal systems shrink spontaneously under curvature driving force at high temperatures. With molecular dynamics simulations, it was found that the reduced mobility, a measure of grain boundary migration rate, is greatly affected by the initial velocity seed, which was unexpected in atomistic simulations. Under an externally applied synthetic driving force (SDF) opposite of the curvature driving force, cylindrical grain boundaries expand, and in some cases, facet. The orientations of the facets formed by a given initial grain boundary orientation are invariant of the driving force magnitude, temperature, and initial grain size. The expanding motions of cylindrical grain boundaries are also affected by initial velocity seeds, given that all other conditions are the same. In this study, the shrinking and expanding motions of isolated cylindrical grain boundaries are explored in depth, which will give more insights into the mechanisms of grain boundary migration. |