Hydrogen generation from Al-Mg-Fe-Sn alloys: a recycling strategy with emphasis on microstructure

Abstract

This project aims to contribute to a better understanding of the hydrogen (H2) generation behavior of Al-Mg-Fe-Sn alloys with focus on the development of correlations with microstructural solidification parameters. Currently, the hydrolysis reaction of Al-based alloys appears to be a promising method for producing H2. However, such a process becomes economically attractive only if such alloys are recycled. It is known that the incorporation of Fe during the recycling of Al-Mg alloys can limit their use in structural applications. Thus, an alternative for reusing these materials is to generate H2. However, an important factor to be considered is the activation of such alloys in corrosion terms. In this sense, the addition of Sn (~1%) can be adopted to favor the H2 evolution reaction through the formation of galvanic cells and breakdown of the passive layer. It should be noted that the research project to which this postdoc will be linked includes the characterization of Al-Sn-Mg alloys for hydrogen generation. In this post-doctorate, the solute contents of the Al-Sn-Mg alloys of the bond project will be maintained, but with the addition of 1%Fe (typical Fe concentration of recycled alloys). Thus, an additional contribution will be to investigate the potential generation of hydrogen from these alloys when recycled. Regarding the methodology, samples will be produced through a directional solidification technique. After the thermal analysis, a broad microstructural characterization will be carried out. In the next phase, samples with different microstructural spacings will be submitted to H2 release tests and potentiodynamic polarization tests. Finally, it is intended to establish mathematical relationships that correlate the quantitative parameters of the microstructure, thermal solidification parameters and H2 generation behavior. (AU)