Work

Mechanical properties of crystalline-amorphous composites: generalization of Hall–Petch and inverse Hall–Petch behaviors

Year: 2025

Type: article

Abstract: The strength, [Formula: see text], of a polycrystal decreases with the mean grain diameter [Formula: see text] for [Formula: see text] atoms (i.e. Hall-Petch behavior) and increases for [Formula: see text] (i.e. inverse Hall-Petch behavior). Our simulations generalize [Formula: see text] to [Formula: see text], where [Formula: see text] is the mean thickness of amorphous grain boundaries of crystalline-amorphous composites. The maximum strength is reached at [Formula: see text] atoms for single-component face-centered-cubic solids and at [Formula: see text] for bidispersed or body-centered-cubic solids because of the different activation stresses of dislocation motions. The results explain recent alloy experiments and provide a way to exceed the maximum strength of polycrystals. Ductility and elastic moduli are also measured in the broad [Formula: see text] space. In regimes without a strength-ductility trade-off, the maximum ductility and ductile-brittle transitions are identified. These results obtained in [Formula: see text] space are important in solid mechanics and can guide the fabrication of crystalline-amorphous composites with outstanding mechanical properties.

Source: National Science Review

DOI: 10.1093/nsr/nwaf336

Authors: Zhibin Xu, Mengmeng Li, Yilong Han

Institution: Hong Kong University of Science and Technology

Language: English

Topic: Microstructure and mechanical properties

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,000

Funder: Research Grants Council, University Grants Committee