Self-blocking of dislocations in intermetallic compound Ni3Ge: Cubic slip
Abstract
Self-blocking of dislocations belonging to the cube plane has been detected in the intermetallic compound Ni3Ge. The nature of cubic slip has been clarified. The experiments included deformation at a temperature above Tmax (the temperature of the yield-stress peak) and subsequent heating without stress. In addition, changes in the dislocation structure upon slow cooling from the temperature of the preliminary deformation have been investigated; in doing so, self-blocking of dislocations has been revealed for the first time. Based on the totality of experimental data, a conclusion has been made on the two-valley potential relief for a dislocation motion in the cube plane. It is the difference in the depths between the Peierls valley (a diffuse core in the cube plane) and the deepest valley (a superpartial dislocation split in the octahedron plane) that provides for the driving force of self-blocking in the absence of an external stress. Different aspects of cubic slip have been considered: the disappearance of cubic slip at T < Tmax and, correspondingly, the nonobservation of an anomalous behavior of the yield stress, as well as the disappearance of octahedral slip at T > Tmax.
- Publication:
-
Physics of Metals and Metallography
- Pub Date:
- April 2011
- DOI:
- 10.1134/S0031918X11030057
- Bibcode:
- 2011PMM...111..385G
- Keywords:
-
- intermetallic compound;
- dislocation;
- plastic deformation;
- blocking;
- self-blocking