| Popis: |
The results of an electron microscopy study of the evolution of the dislocation structure of a polycrystalline ordered and disordered Pd3Fe alloy in the region of weakly stable structural-phase States are presented. The scheme of rearrangement of dislocation substructures during the transition from stage to stage, which are highlighted on the deformation curves of the Pd3Fe alloy, is constructed. It is established that in the case of both disordered and ordered alloys, each stage of deformation is characterized by its own special types of dislocation substructure (DSS), which are the main carriers of deformation for this stage. Transitions from some types of DSS to other types occur in certain ranges of values of the degree of deformation ε. The appearance of the DSS type characteristic of this stage of deformation occurs at the previous stage, and as the degree of deformation increases, the proportion of this type of DSS increases. At the stage under consideration, their share is the largest, and when moving to the next stage, it gradually decreases until it disappears. In the case of ordered alloys, the types of dislocation substructure-the main carrier of deformation for this stage differ from the types of DSS that are implemented in disordered alloys at the same stage of deformation. It is shown that each stage of deformation has its own DSS - strain carriers. When moving to a new stage, the transition to new structural carriers of deformation occurs. During the transition, these carriers co-exist, which is a characteristic feature of weakly stable States of the system. |
