HIGH-TEMPERATURE PLASTICITY AND THE MARTENSITIC-TRANSFORMATION IN LONG-RANGE-ORDERED ALLOYS

It is shown that martensitic transformations can give important information on the structure and mobility of dislocations in long-range-ordered alloys. Most relevant are the energies of the antiphase boundaries which are related to the pair interchange energies, the stacking fault energies and the lattice distortions in the ordered alloys. The alloys which are mainly discussed in this paper are Cu-Zn-Al and Al-Ni, owing to the available detailed studies reported for these systems. It can be expected that further investigations on martensitic transformations, as well as in other ordered alloy systems, will help to clarify the factors that control their plastic behaviour.