What is Recovery, subgrain, dynamic recrystallisation?

Recovery is the rearrangement of dislocations, by climb and cross-slip, into lower-energy arrays, and their annihilation. Dislocations arranged in walls divide a grain into subgrains, parts of the grain whose lattices are tilted by a few degrees from one another. Dynamic recrystallisation is the replacement, during deformation, of strained grains by new grains with fewer dislocations, either by the rotation of subgrains until they become grains, or by the migration of grain boundaries into the more strained neighbours.