ePrints@IIScePrints@IISc Home | About | Browse | Latest Additions | Advanced Search | Contact | Help

Organic monolayers disrupt plastic flow in metals

Sugihara, T and Udupa, A and Viswanathan, K and Davis, JM and Chandrasekar, S (2020) Organic monolayers disrupt plastic flow in metals. In: Science Advances, 6 (51).

Sci-Adv_51_6.pdf - Published Version

Download (3MB) | Preview
abc8900_SM.pdf - Published Version

Download (896kB) | Preview
[img] Video (MP4)
abc8900_Movie_S1.mp4 - Published Version

Download (5MB)
Official URL: https://dx.doi.org/10.1126/sciadv.abc8900


Adsorbed films often influence mechanical behavior of surfaces, leading to well-known mechanochemical phenomena such as liquid metal embrittlement and environment-assisted cracking. Here, we demonstrate a mechanochemical phenomenon wherein adsorbed long-chain organic monolayers disrupt large-strain plastic deformation in metals. Using high-speed in situ imaging and post facto analysis, we show that the monolayers induce a ductile-to-brittle transition. Sinuous flow, characteristic of ductile metals, gives way to quasi-periodic fracture, typical of brittle materials, with 85 reduction in deformation forces. By independently varying surface energy and molecule chain length via molecular self-assembly, we argue that this "embrittlement"is driven by adsorbate-induced surface stress, as against surface energy reduction. Our observations, backed by modeling and molecular simulations, could provide a basis for explaining diverse mechanochemical phenomena in solids. The results also have implications for manufacturing processes such as machining and comminution, and wear. © 2020 The Authors.

Item Type: Journal Article
Publication: Science Advances
Publisher: American Association for the Advancement of Science
Additional Information: Copyright to this article belongs to American Association for the Advancement of Science
Keywords: Embrittlement; Interfacial energy; Metals, Ductile to brittle transitions; Environment-assisted cracking; Liquid metal embrittlement; Manufacturing process; Mechanical behavior; Molecular self assembly; Molecular simulations; Molecule chain lengths, Monolayers
Department/Centre: Division of Mechanical Sciences > Mechanical Engineering
Date Deposited: 12 Feb 2021 06:03
Last Modified: 12 Feb 2021 06:03
URI: http://eprints.iisc.ac.in/id/eprint/67521

Actions (login required)

View Item View Item