MICROMECHANISMS OF PLASTIC-DEFORMATION IN METALS

The paper reviews the macroscopic work hardening behaviour in the diff erent stages of the deformation curve. While for stages II and III the storage of dislocations caused by multislip and their additional anni hilation either via cross slip (low temperatures) or climb thigh tempe ratures) are widely accepted, stages IV and V have found different exp lanations. These are critically discussed in the light of experimental results presently available. The importance of this discussion is inc reased since it has become clear that the strengthening behaviour of n anocrystalline metals produced by severe plastic deformation is govern ed by stage IV - strengthening mechanisms.