Evolution of Dislocation Structure of Polycrystals of Homogeneous Copper-Manganese Solid Solutions Under Conditions of Plastic Deformation

The results of an electron microscopy study of the dislocation structure evolution in polycrystals of Cu-Mn homogeneous solid solutions having an fcc-lattice are presented. A scheme of the dislocation substructure rearrangements identified on the stress-strain curves in the transitions from one stage to another is constructed for the Cu-Mn alloys as a function of the concentration. A critical role of solid solution strengthening in the development of dislocation substructures (DSS) in the Cu-Mn alloys with an fcc crystal lattice is identified, which are the principal deformation carriers for a particular deformation stage. It is shown that the transitions from one DSS type to another occur in specific strain degree intervals epsilon. It is revealed that every deformation stage has its corresponding DSSs - deformation carriers. A stage-to-stage transition is followed by the formation of new deformation carriers, which is a characteristic feature of the low-stability states of this system.