On the activation of recrystallization nucleation sites in Cu and Fe

Rapid thermal heat treatments were used to investigate the early stages of recrystallization in pure iron and copper. The nucleation events for the recrystallization process were observed to take place in the vicinity of triple junctions, grain boundaries and grain interiors. Electron Back-scatter Diffraction (EBSD) was used to measure both the frequency of nucleation events and the misorientation gradients present at each of the above sites. The potency of the nucleation sites was found to increase with the local misorientation gradient. A simple physically based model was developed to predict the incubation time for the formation of recrystallization embryos in the vicinity of each site. This model can be coupled to existing recrystallization and growth models to produce a more complete description of the recrystallization processes including the competition between nucleation sites.