VT Professor Receives Grants to Investigate Corrosion of Manufactured Metals

Yao Fu, assistant professor in the Kevin T. Crofton Department of Aerospace and Ocean Engineering, is the recipient of a Faculty Early Career Development Program award from the National Science Foundation, as well as a Young Investigator Program award from the Office of Naval Research. Photo courtesy of Peter Means/Virginia Tech.

Yao “Yolanda” Fu, an assistant professor in the Kevin T. Crofton Department of Aerospace and Ocean Engineering at Virginia Tech (VT) (Blacksburg, Virginia, USA), was a recent recipient of two prestigious research grants to study the environmental-related behaviors of additively manufactured metals. Fu received a $594,948 Faculty Early Career Development Program (CAREER) grant from the National Science Foundation and a $509,878 Young Investigator Program (YIP) grant from the Office of Naval Research.

With her CAREER grant, Fu will seek to answer two prevailing questions about additively manufactured metals: how the fatigue behavior of these alloys differs from their conventionally manufactured counterparts under both normal and corrosive environments, and how the unique microstructures of additive manufactured alloys contribute to those behavioral differences.

Using both experimentation and computational methods, Fu and her research team will investigate how additive manufactured metals react under tensile/compressive testing and high-cycle fatigue testing. From there, the team will perform similar tests in corrosive environments and examine environmental factors such as varying temperatures, humidity, and salinity levels.

Insights gained from Fu’s research will guide the design and manufacturing of additively manufactured parts. In understanding their unique microstructural features and their effects on fracture and cracking in a corrosive environment, the researchers hope to develop parts with prolonged service life and limited fatigue failure, which in turn will reduce financial losses related to corrosion damage.

With her YIP grant, Fu will examine stainless steels often used in marine environments, particularly the performance of hybrid structures that consist of partially printed and partially conventionally processed parts. These hybrid steel structures will enable Fu and her team to evaluate how their environmentally assisted cracking behavior differs from that of their conventional or bulk counterparts. In addition, Fu will investigate how the material’s solidification texture and grain directionality have a direct effect on corrosion-related properties over a wide range of temperatures.

As part of that investigation, Fu will study corrosive behaviors in sodium chloride solutions with concentrations close to that of seawater, which includes an electrochemical analysis of the corrosion characteristics, stress corrosion cracking, high cycle fatigue, and crack propagation testing in the corrosive environment.

By understanding the underlying mechanisms that lead to corrosion, cracking, and failure, researchers will be better equipped to control features and defects during the manufacturing process. One potential application that is of particular interest to the Office of Naval Research is improvements to additive manufactured 316L stainless steel, which inevitably corrodes due to significant saltwater exposure.

Source: Virginia Tech, https://vtx.vt.edu.