A model to explain extensive superplasticity in polycrystalline materials

Lee has proposed a model, which consists of hexagonal single-phase grains of uniform size loaded in tension, to show grain rearrangement process by Coble creep and GB migration. The model shows a probable way to switch grain neighbors, resulting in a strain while retaining the equiaxed grain structure. The Lee model can operate in the slant loading direction as described by several representative steps. The extendable Lee model gives a reasonable physical path for explaining the extensive superplasticity observed in polycrystalline materials. The model physically demonstrate that the extensive superplasticity in polycrystalline materials might occur by repeatedly switching grain neighbors during Coble creep.