Like other interfaces, equilibrium grain boundaries were smooth at low temperature and rough at high temperature; however, little attention was paid to roughening except for faceting boundaries. Using molecular dynamics simulations of face-centred cubic Ni, two closely related grain boundaries with different boundary planes were studied. In spite of their similarity, their boundary roughening temperatures differed by several hundred degrees, and boundary mobility was much larger above the roughening temperature. This had important implications for microstructural development during metallurgical processes.
Grain Boundary Interface Roughening Transition and its Effect on Grain Boundary Mobility for Non-Faceting Boundaries. D.L.Olmsted, S.M.Foiles, E.A.Holm: Scripta Materialia, 2007, 57, 1161-4