Exceptional Microscale Plasticity in Amorphous Aluminum Oxide at Room Temperature
Loading...
Access rights
openAccess
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This publication is imported from Aalto University research portal.
View publication in the Research portal
View/Open full text file from the Research portal
Other link related to publication
View publication in the Research portal
View/Open full text file from the Research portal
Other link related to publication
Date
2023-11-16
Department
Major/Subject
Mcode
Degree programme
Language
en
Pages
14
Series
Advanced Materials, Volume 35, issue 46
Abstract
Oxide glasses are an elementary group of materials in modern society, but brittleness limits their wider usability at room temperature. As an exception to the rule, amorphous aluminum oxide (a-Al2O3) is a rare diatomic glassy material exhibiting significant nanoscale plasticity at room temperature. Here we show experimentally that the room temperature plasticity of a-Al2O3 extends to the microscale and high strain rates using in situ micropillar compression. All tested a-Al2O3 micropillars deform without fracture at up to 50% strain via a combined mechanism of viscous creep and shear band slip propagation. Large-scale molecular dynamics simulations align with the main experimental observations and verify the plasticity mechanism at the atomic scale. The experimental strain rates reach magnitudes typical for impact loading scenarios, such as hammer forging, with strain rates up to the order of 1 000 s−1, and we expand the total a-Al2O3 sample volume exhibiting significant low-temperature plasticity without fracture by 5 orders of magnitude from previous observations. The discovery is consistent with the theoretical prediction that the plasticity observed in a-Al2O3 can extend to macroscopic bulk scale and suggests that amorphous oxides show significant potential to be used as light, high-strength, and damage-tolerant engineering materials.Description
Keywords
glasses, oxides, plasticity, pulsed laser deposition, micropillar compression, molecular dynamics simulations, finite element modelling
Other note
Citation
Frankberg, E J, Lambai, A, Zhang, J, Kalikka, J, Khakalo, S, Paladino, B, Cabrioli, M, Mathews, N G, Salminen, T, Hokka, M, Akola, J, Kuronen, A, Levänen, E, Di Fonzo, F & Mohanty, G 2023, ' Exceptional Microscale Plasticity in Amorphous Aluminum Oxide at Room Temperature ', Advanced Materials, vol. 35, no. 46, 2303142 . https://doi.org/10.1002/adma.202303142
