MSE Seminar Series: Aeriel Leonard (Ohio State)

Description

Understanding Dislocation-Precipitate Interactions in Microstructurally & Compositionally Complex Alloys

Microstructurally and compositionally complex alloys (MCCA) such as Nickel-Aluminum-Bronze (NAB) are important to Navy and maritime applications due to their high strength, toughness, and fatigue resistance, as well as excellent corrosion resistance. NAB’s are widely used in many naval applications including ship propellers, underwater fasteners, pumps, and valves. Traditional sand cast NAB alloys tend to have a large amount of waste material, and reduced complexity in component geometry due to the limitations of the casting processing. As a result, NAB alloys are emerging as a viable alloy for additive manufacturing (AM) and therefore provides a new space to establish fundamental relationships between AM processing, structure and properties. Of the additive processes, wire arc additive manufacturing (WAAM) is an evolving technology for fabricating large-scale, near net shape NAB components. It is understood that the high cooling rates achieved in WAAM prevent the precipitation of coarse rosette-like KI phase which usually form during the latter stages of solidification during the casting process. In this work, the dislocation interactions with interfaces such as grain boundaries and precipitates will be used to understand fatigue life and crack initiation and growth behavior in these alloys during low-cycle and high-cycle fatigue.
 

Bio:
Aeriel D.M. Leonard is an Assistant Professor of Materials Science and Engineering. Dr. Leonard’s research interest is combining advanced characterization with in-situ experiments to quantify relationships between manufacturing/processing, micro/macro structures, and mechanical behavior in microstructurally and compositionally complex alloy systems, additive manufactured materials, and magnesium alloys.

She earned her Bachelor’s Degree in Metallurgical and Materials Engineering from the University of Alabama in 2012. After completing her Bachelor’s degree, Dr. Leonard worked in the Corrosion Research Group at Alstom Inc. for a year.

In 2013, she began her Ph.D. journey at the University of Michigan in Materials Science and Engineering. Dr. Leonard’s Ph.D. work investigated real-time microstructural and deformation evolution in magnesium alloys using advanced characterization techniques such high energy diffraction microscopy and electron back scatter diffraction. While at the University of Michigan, she led and worked on many teams aimed at increasing the number of underrepresented minorities in engineering, including developing and implementing a leadership camp for female engineering students in Monrovia, Liberia.

Dr. Leonard was awarded an NRC Postdoctoral Fellowship at the U.S, Naval Research Laboratory in Washington DC where she worked for two years. During this time, she used advanced characterization techniques such as x-ray computed tomography and high-energy diffraction microscopy to understand damage and texture evolution during in-situ loading in additive manufactured materials.