A NEW THEORETICAL CONCEPT FOR MICROGRAIN SUPERPLASTICITY PROVIDING THE PREDICTION OF THE OPTIMUM CONDITIONS FOR SUPERPLASTIC DEFORMATION

The superplasticity phenomenon is considered as a particular example o f the structure-mechanical behavior of polycrystals during plastic def ormation. Based upon the common principles of the plastic deformation of polycrystal materials the fundamental principle of achieving high p lasticity is suggested. This principle is assumed to reflect the basic nature of the superplasticity phenomenon. On the basis of the concept involved the experimental procedure to find out the full set of the o ptimum conditions for superplastic deformation is developed. The appli cability of the method suggested is demonstrated on the example of the intermetallic compound TiAl.