Strengthening mechanisms and dislocation processes in <111> textured nanotwinned copper

Authors

Xing Zhao, University of WollongongFollow
Cheng Lu, University of WollongongFollow
Anh Kiet Tieu, University of WollongongFollow
Linqing Pei, University of WollongongFollow
Liang Zhang, University of WollongongFollow
Kuiyu Cheng, University of WollongongFollow
Minghui Huang, Central South University

RIS ID

109638

Publication Details

Zhao, X., Lu, C., Tieu, A. Kiet., Pei, L., Zhang, L., Cheng, K. & Huang, M. (2016). Strengthening mechanisms and dislocation processes in textured nanotwinned copper. Materials Science and Engineering A: Structural Materials: Properties, Microstructure and Processing, 676 474-486.

Abstract

We use molecular dynamics simulations to elucidate the deformation mechanisms of textured nanotwinned materials under tensile loading parallel to the twin boundary (TB). Our simulations reveal that the tensile strength of nanotwinned Cu increases monotonically as the twin spacing decreases. The strengthening effect mainly results from TB restricting the transmission of dislocations across the TB. Throughout the simulations the transmissions of dislocations across the TBs dominate the plastic deformation. Both direct and indirect transmissions are identified at atomic level. Direct transmission involves either successive transmission of the leading and trailing partials as in the Fleischer cross-slip model or absorption and desorption of the extended dislocation as in the Friedel-Escaig cross-slip mechanism. In contrast, indirect transmission involves the formation of special superjogs. The persistent slip transfer leaves zigzag slip traces on the cross-sectional view and the inhomogeneous deformation leads to the formation of intersecting slip bands on the plane view.