Michael Rademacher

Advisor: Prof. Stebner

will propose a doctoral thesis entitled:
Ultrasonically atomized nanogalvanic aluminum powder for hydrogen gas production.

On

Friday, February 27th at 10:30 a.m.
Love 183

and 

 Virtually via https://teams.microsoft.com/meet/26753790405070?p=MuhpiEiJmKnlqlSKPv

Committee
            Prof. Aaron Stebner – School of Materials Science and Engineering (advisor)
            Prof. Josh Kacher– School of Materials Science and Engineering
            Prof. Preet Singh – School of Materials Science and Engineering

      Prof. Rick Neu – School of Mechanical Engineering
            Dr. Kris Darling – Army Research Lab

Abstract
      Hydrogen fuel cells are an effective way to ensure access to electricity in even the harshest environments. Currently, the US military imports most of its energy supplies from outside of its bases—often at a high monetary and human cost. At the same time, US military bases generate large quantities of waste. Specifically, scrap aluminum and gray water. It is well known that aluminum reacts readily with water to produce hydrogen gas, but this reaction passivates quickly at the surface of the aluminum. Two simultaneous strategies serve to mitigate this passivation. First, maximizing the surface area of produced powder allows more of the bulk of each sample to react. Second, precisely alloying anodic aluminum with dissimilar cathodic metals—namely tin and bismuth—to create a galvanic couple and thus increase the reaction rate between aluminum and water to such an extent that it outpaces the passivation rate experienced at the surface, allowing for the reaction to move inwards into the bulk of the aluminum particles. The problem presented here is to make powder with sufficient surface area, and with the optimal microstructure for the galvanic couple, to achieve high reaction yields.

      This study aims to employ ultrasonic atomization to make nanogalvanic aluminum powder for use in hydrogen generation. To accomplish this goal, several objectives must be met. First, optimizing the ultrasonic atomization process to produce the desired microstructure for nanogalvanic aluminum powder. To support this optimization, the development of coatings in both the atomizing and melting apparatuses to limit impurity pickup during powder production. Next, determining the optimal microstructure that most fully realizes the hydrogen-yielding potential of this nanogalvanic powder. Finally, the design and implementation of a meltpool flow model for atomization process control and outcome prediction. These goals, if met, will result in reproducible nanogalvanic aluminum powder that optimally delivers hydrogen gas upon exposure to water.