A simple question really has a long answer.
Dislocations are responsible for the malleability of metals. Dislocations are imperfections in the lattice structure that allow movement of the material. As you work harden, more and more dislocations are produced but these intertwine with each other and 'pinning' point in the lattice such as interstitial atoms.
Annealing allows the materials to flow and the lattice to re-arrange itself so it will again flow at a lower stress.
The temperatures would be very high and for annealing are greater than 1/2Tm.-Dick
Last edited by Dick_dup1; 10/27/11 05:55 PM.