|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Grain Boundaries and Interfaces: Metastability, Disorder, and Non-Equilibrium Behavior
||G-27: Fractal-like Grain Exfoliation in Liquid-metal-activated Aluminum-water Reactions
||Peter Godart, Douglas Hart
|On-Site Speaker (Planned)
Understanding aluminum-water reactions is critical for applications ranging from corrosion prevention to hydrogen generation. It has been shown that such reactions can be accelerated by the introduction of liquid metal phase into the grain boundary network of the aluminum. Little was known about the exact mechanism by which this process occurs, though, in part due to challenges with using analysis techniques like SEM and XRD in a highly dynamic aqueous environment. In this work, a method is presented for reacting aluminum treated with a eutectic gallium indium alloy with water arbitrarily slowly via controlled exposure to room-temperature water vapor, enabling in-progress analysis via SEM and XRD techniques. Using this approach, a two-part reaction mechanism was observed for the first time in which the aluminum first disintegrates along its micro- and nano-scale grain boundaries via a fractal-like exfoliation process, followed by the reaction between unpassivated aluminum grains and ambient water molecules.
||Aluminum, Energy Conversion and Storage, Mechanical Properties