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Recovery plays distinct roles in nanostructured and coarse-grained metallic materials. While static and dynamic recovery usually soften work-hardened, coarse-grained materials, static recovery has been shown to strengthen nanostructured metals. This study extends this understanding by demonstrating that dynamic recovery can also strengthen nanostructured metals under deformation. Tensile, creep, and plane strain compression tests on nanostructured aluminum reveal a trend of increasing strain-hardening with decreasing strain rate and increasing temperature. Molecular dynamics simulations further indicate that sudden strain rate reductions lead to an initial drop in flow stress, followed by strain hardening. These findings suggest that dynamic recovery could serve as an effective strengthening mechanism for nanostructured metals, offering improvements in uniform elongation.
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Electrochemical Healing of Fractured Metals
Abstract Repairing fractured metals to extend their useful lifetimes advances sustainability and mitigates carbon emissions from metal mining and processing. While high‐temperature techniques are being used to repair metals, the increasing ubiquity of digital manufacturing and “unweldable” alloys, as well as the integration of metals with polymers and electronics, call for radically different repair approaches. Herein, a framework for effective room‐temperature repair of fractured metals using an area‐selective nickel electrodeposition process refered to as electrochemical healing is presented. Based on a model that links geometric, mechanical, and electrochemical parameters to the recovery of tensile strength, this framework enables 100% recovery of tensile strength in nickel, low‐carbon steel, two “unweldable” aluminum alloys, and a 3D‐printed difficult‐to‐weld shellular structure using a single common electrolyte. Through a distinct energy‐dissipation mechanism, this framework also enables up to 136% recovery of toughness in an aluminum alloy. To facilitate practical adoption, this work reveals scaling laws for the energetic, financial, and time costs of healing, and demonstrates the restoration of a functional level of strength in a fractured standard steel wrench. Empowered with this framework, room‐temperature electrochemical healing can open exciting possibilities for the effective, scalable repair of metals in diverse applications.
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- PAR ID:
- 10419014
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 35
- Issue:
- 24
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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