Research Aims to Reduce the Processing Cost and Increase the Strength and Formability of Magnesium Alloys.

Sean Agnew, professor of materials science and engineering at the University of Virginia School of Engineering, has joined a nation-wide effort to make the process of discovering, developing, manufacturing and deploying advanced materials at least twice as fast as it is now, and much less costly. This is the vision of the Materials Genome Initiative for Global Competitiveness, funded in part through the National Science Foundation’s interdisciplinary program Designing Materials to Revolutionize and Engineer our Future.

The program has awarded Agnew and his co-principal investigators a four-year, $1.75 million grant to reduce the processing cost and increase the strength and ductility (i.e., formability) of magnesium alloys. As the lightest of all structural metals, magnesium alloys have great potential for applications in which weight is critical to performance and efficiency, such as the automotive, rail and aerospace industries.

Agnew leads the effort as principal investigator; his primary focus is modeling and characterizing the mechanical behavior of the alloys. Joining the team as co-principal investigators are assistant professor Bi-Cheng Zhou, also with the UVA Department of Materials Science and Engineering; James M. Howe, UVA Thomas Goodwin Digges Professor of Materials Science and Engineering and director of the Nanoscale Materials Characterization Facility; and Derek Warner, associate professor of civil and environmental engineering at Cornell, a leader in the field of atomistic modeling of materials deformation.

Zhou, Howe and Warner will guide alloy design strategies involving Guinier-Preston zones. These are nanoscale alloying elements in metal materials that group together through nucleation and growth progressions. Zhou and Warner are tasked, respectively, with modeling Guinier-Preston zone nucleation and deformation, while Howe will use the department’s newly installed FEI-manufactured Scanning Transmission Electron Microscope and its state-of-the-art detector technologies to characterize the structure of the zones. The team’s combined efforts will generate new knowledge pertaining to the structure and formation of the zones, as well as their impact on the deformation behavior of the alloys. Their project will build upon recent studies by Japanese collaborators which demonstrated that magnesium alloys with very high number densities of Guinier-Preston zones can be produced using abundant, low-cost ingredients, while gaining strength and maintaining their ductility.

The research conducted for the National Science Foundation’s Designing Materials to Revolutionize and Engineer our Future program leverages Agnew’s contributions to the development of magnesium sheet alloys and processes that can be formed at temperatures low enough to permit manufacturers to employ conventional, steel stamping dies and lubricants. Agnew and his fellow researchers are addressing the remaining obstacle to wholesale application of magnesium alloy sheet materials: cost. Magnesium metal is not expensive, but the conversion costs of wrought processing—from casting to a semi-finished sheet—plus the cost of sophisticated processes necessary to form, join, and address corrosion protection remain prohibitively high.

The team will kick off its work in January 2020, taking advantage of the fall term to recruit the best student talent to the program. Over the next four years, they will educate a diverse group of students and postdoctoral fellows, providing them with the skills required to succeed in interdisciplinary and international teams comprised of computational and experimental researchers. They will also gain the satisfaction of performing research that benefits the U.S. manufacturing, transportation and defense sectors.