Influence of bimetal interface confinement on the Hall-petch slope of multiscale Cu/Nb multilayer composites

Chaogang Ding; Jie Xu; Debin Shan; Bin Guo; Terence G Langdon

doi:10.1016/j.heliyon.2023.e16231

Influence of bimetal interface confinement on the Hall-petch slope of multiscale Cu/Nb multilayer composites

Heliyon. 2023 May 12;9(5):e16231. doi: 10.1016/j.heliyon.2023.e16231. eCollection 2023 May.

Authors

Chaogang Ding^{1

2}, Jie Xu^{1

2}, Debin Shan^{1

2}, Bin Guo^{1

2}, Terence G Langdon³

Affiliations

¹ National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin, 150001, China.
² Key Laboratory of Micro-systems and Micro-structures Manufacturing of Ministry of Education, Harbin Institute of Technology, Harbin 150001, China.
³ Materials Research Group, Department of Mechanical Engineering, University of Southampton, Southampton SO17 1BJ, UK.

Abstract

Heterostructured materials afford a new way to improve the mechanical properties, which has become vital in both materials science and engineering applications. In the present research, Cu/Nb multilayer composites with layer thicknesses from the micrometer to nanometer were fabricated by accumulative roll bonding and the microstructure and mechanical properties of the Cu/Nb multilayer composites were then investigated. The yield strength and ultimate tensile strength of these composites increase with decreasing layer thickness. Moreover, the relationship between yield strength and (layer thickness)^-1/2 approximately accords with the conventional Hall-Petch equation but with a decrease in the Hall-Petch slope when the layer thickness decreases from the micrometer to nanometer scales. The deformation microstructure of these Cu/Nb multilayer composites clearly exhibit dislocations glide in the layers, which reduces the stacking of dislocations at the Cu-Nb interface and thereby weakens the strengthening effect of the interface.

Keywords: Cu-Nb; Hall-petch relationship; Interfaces; Multilayer structures; Tensile strength.