A Model of Dynamic Recrystallization in Alloys during High Strain Plastic Deformation

Recrystallized grains, less than 200 nm in diameter were observed in heavily shear zones of a high strength low alloy steel and a Ni-based alloy, and Also grain refinement, less than 3 μm in diameter was made in high purity aluminum by ECAE at ambient temperature. The experimental results showed that high strain rate and large deformation could induce dynamic recrystallization. Based on dislocation dynamics and grain orientation change enhanced by plastic deformation, a model for the recrystallization process is developed. The model is used to explain the ultra fine grains which are formed at a temperature still much lower than that for the conventional recrystallization.