Hits:

Indexed by:期刊论文

Date of Publication:2019-01-30

Journal:JOURNAL OF PHYSICS D-APPLIED PHYSICS

Included Journals:SCIE、Scopus

Volume:52

Issue:5

ISSN No.:0022-3727

Key Words:nanotwinned copper; nanovoid; mechanical property; molecular dynamics simulation; uniaxial tension

Abstract:Molecular dynamics simulations are performed to analyze the uniaxial tensile deformation behaviors of nanotwinned copper bulk containing pre-existing multiple spherical/ellipsoidal voids. The effects of twin-boundary spacing, initial void size, void fraction, void shape, void orientation angle and loading orientation on the mechanical properties are examined by considering the stress-strain response and dislocation activity. Results illuminate that the coherent twin boundary can significantly enhance the strength of bulk copper. The critical stress for dislocation emission in the copper specimen depends mainly on the size of voids, which can influence the yield stress of nanotwinned copper. Less stress is required to emit dislocations from larger voids than smaller ones. In general, the larger initial void porosity is accompanied by smaller elastic modulus and critical stress. Furthermore, it is found that different dislocation patterns can be triggered under different loading orientations.