Influence of Composition on the Evolution of Dislocation Substructure in the Low-Stability State Polycrystalline Cu-Al Alloys under Plastic Deformation

New concepts of dislocation physics of plasticity and strength are considered using quantitative methods of transmission diffraction electron microscopy. New concepts of dislocation physics of plasticity and strength are considered using quantitative methods of transmission diffraction electron microscopy. The analysis of changes in the parameters of the dislocation substructure (DSS) is given on the example of alloys Cu-0.5 and 14 аt. % Al and the influence of these parameters on the change in the substructure of the material at a temperature T=293 K is considered. It is shown that at each stage of deformation, there are usually two substructures ("old" and "new"). The blurring of the transition from stage to stage is associated with the presence of weakly stable pre-transition structural-phase States at certain degrees of deformation of several types of substructures simultaneously, i.e., a weakly stable structural-phase state of the system. Against the background of the "old" substructure, a "new" one is born, which in the process of deformation becomes the main one, and then the "old" one, in the depths of which another substructure is formed. Experimental evidence of this regularity is obtained for FCC alloys. The presence of grain boundaries complicates the diagrams: a third substructure is formed near the grain boundaries, which corresponds to the following substructures (later) in the sequence of DSS transformations.

Transpyrenean Encounter on Advanced Materials

TEAM1 has taken place in Sete (France) on 4, 5, 6 july 2017. It has gathered a little less than 40 participants who presented communications on various fields of advanced materials, and on experimental facilities or experimental methods, that are briefly summarized in the present volume. Presented abstracts deal with fullerenes, graphene, thin films, oxides, ferroelectrics, pyroelectrics, piezoelectrics, superconductors, nanomaterials, photovoltaics, X-ray diffraction, electron diffraction, electron microscopy, electron holography, carbon nanotubes, nanorods, ZnO.

EFFECT OF NANOSTRUCTURE OF THE PLATING ALLOY CO-NI-CR ON THE COATING MICROHARDNESS

The article reviews application of the methods of X-ray diffraction, electron microscopy, micro-roentgen-spectral analysis to study the structure and to prove a presence of nanostructures in the electrodeposition of the alloy Co-Ni-Cr. It was shown that the nanostructures obtained owe their origin to introduction of a residue of chromium amorphous hydroxide compounds.