Effects of constituting material and interfacial crack on mechanical response of nanoscale metallic bilayers – a quasi-continuum study

ABSTRACT

The effects of the constituting material and an interfacial crack on the deformation and mechanical response of metallic bilayer films under tension are studied using quasi-continuum simulations in terms of atomic trajectories, stress distribution and the stress–strain curve. The simulation results show that bilayer films with identical constituting monolayers have higher tensile strength than that of those with different monolayers. For bilayer films with different monolayers, the layer interface acts as a barrier that resists dislocation propagation. Dislocation emission at a crack tip blunts the tip. Necking originates at the layer interface and develops on monolayers with relatively low strength. A rectangular crack is less likely to develop than a V-shaped crack.

KEYWORDS:

• Bilayer films
• quasi-continuum method
• stress distribution
• crack
• dislocation

Acknowledgments

The authors acknowledge the support by the Ministry of Science and Technology, Taiwan, under grant number MOST 109-2221-992-009-MY3.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Ministry of Science and Technology, Taiwan: [Grant Number MOST 109-2221-992-009-MY3].