A THEORETICAL DESCRIPTION OF THE 2-STEP DEFORMATION OF INTERMETALLICS

The paper deals with the analysis of the two-step deformation of inter metallics where the yield stress possesses a temperature anomaly. Diff erent schemes of deformation were studied. The principal differences b etween the schemes are whether the transition from one step of deforma tion to the other is accompanied by increasing or decreasing temperatu re and whether the said transition takes place at a high or low degree deformation. A unified approach to the description of the two-step de formation is proposed. The approach considers that for the plastic flo w to occur, it is necessary to overcome, on the one hand, the thermall y active blocking of dislocation sources and, on the other hand, elast ic stress fields of the existing dislocation structure. (C) 1997 Elsev ier Science S.A.