ERI: Manufacturability of Novel High Temperature Aluminum Alloys Through Additive Manufacturing Cycle

Marquette University, Milwaukee WI

Investigators

Abstract

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Metal additive manufacturing, also known as metal 3D-printing, offers unprecedented capabilities in manufacturing highly complex or customized components. Metal additive manufacturing finds many applications in the aerospace, automotive and energy industries and has the potential to revolutionize future manufacturing. However, most metals after additive manufacturing show undesired defects, which deteriorate the reliability and shorten the lifetime of the components. This Engineering Research Initiation (ERI) grant will support fundamental research that will contribute to new knowledge in how to reduce defects during the additive manufacturing and post-processing of a new high temperature aluminum alloy. The outcome of the research will enable an improved control of defects in additively manufactured metallic components and provide a new alloy design method for developing aluminum alloys. The research involves activities combining advanced manufacturing and materials science, which offers training opportunities to graduate students, promotes undergraduate research and provides outreach activities to diverse groups of younger students. This research will broadly impact the manufacturing industry by facilitating the implementation of metal additive manufacturing and promoting its consistency, all the while training students as future leaders in advanced manufacturing. Additive manufacturing of lightweight aluminum alloys has been a major challenge due to their propensity for formation of defects. Specifically, during the laser powder bed fusion of most traditional aluminum alloys, pores and/or cracks are observed despite optimization of the processing parameters. Post-processing is therefore inevitable to reduce or eliminate the defects in the materials, which can coarsen their microstructure and reduce their mechanical performance. The goal of this research is therefore to fundamentally understand the defect generation and elimination mechanisms during additive manufacturing and its post-processing and develop novel high temperature lightweight aluminum alloys that are highly manufacturable. Experiments combining manufacturing, advanced characterization and high temperature creep testing will be performed on a coarsening-resistant aluminum alloy specifically designed for the additive and post-processing cycle. The research will establish the relationship between the defects and processing parameters, develop a mechanistic model for the pore closure kinetics during the post-processing, and determine the creep property and deformation mechanisms of the new aluminum alloy. The research will address the knowledge needed to develop metallic alloys specifically amenable to additive manufacturing and fill the knowledge gap in the understanding of creep mechanisms in additively manufactured metallic alloys. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.