Oxide glasses are an elementary group of materials in modern society, but their intrinsic brittleness limits their usability at room temperature. As an exception to the rule, recent discovery shows that amorphous aluminum oxide (a-Al₂O₃) is a rare diatomic glassy material exhibiting significant nanoscale plasticity at room temperature (Frankberg et al. Science 2019, 366, 864). Later, the discovery was expanded to show that room temperature plasticity of a-Al₂O₃ extends to the microscale and high strain rates associated with impact-type loading, such as hammer forging, or frontal car collisions (Frankberg et al. Adv. Mater. 2023, 2303142). Notably, the low temperature plasticity of a-Al₂O₃ is not limited to compression but has been demonstrated also in microscale bending using free-standing samples (Mathews & Frankberg et al., under review). Pure aluminum oxide is known to be a poor glass former and requires specialized synthesis techniques to form the amorphous/glassy phase. The plasticity is shown to be directly linked to the glass forming ability and glass transition occurring in pure aluminum oxide (Zhang et al. J. Non-Cryst. Solids 2024, 628, 122840). Prediction made based on the data is that the observed plasticity can extend to millimeter-thick a-Al₂O₃ sheets, and by that the material shows significant future potential to be used as a light, high-strength, and damage-tolerant engineering material. These findings propose a shift in the paradigm towards ductile glass materials, and offers collaboration opportunities between academia and industry to further develop manufacturing processes needed for the scaled-up production of a-Al₂O₃. The foreseen applications include coatings, such as protective and barrier films for electronics, batteries and hydrogen infra, and ultra-thin glass (UTG) films, to induce a leap in the damage-tolerance of smart devices and foldable touch screens.
Erkka Frankberg
Ductile glass at room temperature
Company: Tampere University, Finland
About the speaker:
Entrepreneurial Researcher interested in solving some of the toughest challenges in Materials Science. We have discovered an oxide glass material that does not break, but yields and plastically deforms at room temperature. We want to understand what gives glass these new, superior properties. Because if we understand how the properties of a material emerge, we can start manufacturing it, in the future even at industrial scale.
