Papers by Author: A.V. Kuznetsov

Abstract: Commercial purity copper was subjected to ECAP and subsequent cold rolling. Structure and mechanical properties were studied using EBSD analysis, TEM and tensile tests. Effect of ECAP number passes on grain size and fraction of high angle boundaries after cold rolling was investigated. Rolling results in grain refinement and HABs fraction increase the more ECAP number passes. UTS increases significantly after rolling. Increase of strength is accompanied by loss of plasticity. Evolution of microstructure and mechanical properties is discussed.

Abstract: Evolution of micro- and macrostructure and mechanical properties of oxygen-free copper after MAF at room temperature was studied. MAF included sequential upsetting and drawing with total cycles number equal to 20 and maximum strain ≈50. MAF causes the formation of homogenous UFG structure with a grain/subgrain size of 0.3 m and fraction of high angle boundaries 50%, but macrostructure is heterogeneous. Rough shear macrobands areas of different orientation are observed. MAF results in significant strengthening from 280 MPa to 445 MPa, but samples remain very ductile even after large strains. Mechanisms of UFG structure formations during MAF are discussed.