Papers by Author: N.F. Yunusova

Abstract: Microstructure and mechanical properties of the ultrafine-grained (UFG) 1421 aluminum alloy processed by equal channel angular pressing (ECAP) have been studied. This UFG material was successfully rolled under the conditions of superplasticity. It was established that the rolled material exhibited not only the enhanced superplasticity, but also high strength retaining initial ductility at room temperature after additional short-term annealing and low-temperature aging.

Abstract: The ultrafine-grained (UFG) 1421 aluminum alloy processed by equal channel angular pressing (ECAP) has demonstrated enhanced superplasticity at low temperature and high strain rates. This UFG material was successfully rolled at temperatures of 330-370oC retaining small grain size and equiaxed grain structure. The microstructure of the UFG alloy subjected to warm rolling (WR) was studied, and the mechanical properties of the ECAP+WR samples with UFG structures were investigated. We have found that the rolled material exhibited not only the enhanced superplasticity, but also high strength at room temperature.

Abstract: Recent studies have demonstrated that ultrafinе-grainеd (UFG) alloys processed by equal channel angular pressing (ECAP) and high pressure torsion (HPT) can exhibit enhanced supеrplacticity at relatively low temperature and/or high strain rates. At the same time severe plastic deformation (SPD) of aluminium alloys is often carried out at elevated temperatures leading to various grain size and volume fraction of precipitates. The significance of the SPD temperature for commercial 1420 and 1421 aluminium alloys has been evaluated in this paper using in-situ heating of thin foils in the column of a transmission electron microscope. Superplastic characteristics of alloys processed at various ECAP temperatures are discussed.