Microstructure and mechanical behavior of UFG copper processed by ECAP following different processing regimes

PÜRÇEK G., Saray O., Nagimov M. I., Nazarov A. A., Safarov I. M., Danilenko V. N., ...More

PHILOSOPHICAL MAGAZINE, vol.92, no.6, pp.690-704, 2012 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 92 Issue: 6
  • Publication Date: 2012
  • Doi Number: 10.1080/14786435.2011.634842
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.690-704
  • Karadeniz Technical University Affiliated: Yes


Commercially pure (99.9%) copper was severe plastically deformed by equal-channel angular pressing (ECAP) following route-Bc in three different processing regimes in order to obtain ultrafine-grained (UFG) microstructures leading to improved mechanical properties. In regime-1, the billets were processed at room temperature up to eight passes. The billets were processed at 200 degrees C up to eight passes in regime-2. Regime-3 is a hybrid regime by which the billets were deformed at 200 degrees C up to four passes first, and these billets were then processed at room temperature for one, two and four passes. In all regimes, the ECAP processing results in a refinement of the conventionally grained (CG) initial microstructure of copper down to sub-micron level leading to a great improvement in the strength as compared to CG copper. Among the regimes applied, regime-3 was found to be the best regime for improvement in strength along with adequate ductility. The samples showed more than eight times increases in yield strength after processing in regime-3 for 4 + 4 passes, from 47 MPa for CG copper to about 408 MPa for the UFG sample. Such improvement in strength was accompanied by a 16.9% total elongation and 6% uniform elongation. The processing in regime-2 resulted in the best elongation to failure of about 22% after eight passes, but it gave the lowest strength values among others.