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

L.I Trischkina,T.V Cherkasova,V.V Kulagina,A.I Potekaev,A.A Klopotov

doi:10.14258/izvasu(2021)1-09

Abstract

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.

Highlights

Рассматриваются новые представления дислокационной физики пластичности и прочности с применением количественных методов просвечивающей дифракционной электронной микроскопии
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 the "old" one, in the depths of which another substructure is formed. Experimental evidence of this regularity is obtained for FCC alloys

Summary

Introduction

Рассматриваются новые представления дислокационной физики пластичности и прочности с применением количественных методов просвечивающей дифракционной электронной микроскопии. Что на каждой стадии деформации присутствует, как правило, две субструктуры («старая» и «новая»). Целью данной работы является исследование влияния состава на эволюцию дислокационной субструктуры в поликристаллических сплавах Сu–Al при пластической деформации. 2. Результаты и их обсуждение На рисунке 1 представлены зависимости напряжения течения σ и коэффициента деформационного упрочнения θ=ds/dε от степени деформации εист в сплаве Cu–0.5 ат.% А1 и 14 ат.% А1.

Results

Conclusion