MAE Seminar: Additive Manufacturing of Structural Materials - Processing-Structure-Property Relationships
Abstract: Additive manufacturing (AM) of metallic materials, a layer-by-layer fabrication technique, has potential application in custom and complex-shaped structural components that cannot be made through traditional casting or subtractive machining methods. However, before AM can be adopted for use in structural applications, the processing-structure-property relationships in these materials must be understood such that their mechanical properties can be reliably predicted. I will focus on laser- and powder-based directed energy deposition (DED) AM in which a laser creates a melt pool on a substrate or a previous layer of solid material, and powder is flowed directly to the melt pool through a set of nozzles. As the laser moves to create the geometry of the single layer, the melt pool rapidly solidifies and fuses to the layer below. The rapid solidification, followed by repeated thermal cycles exposes the material in AM to complex thermal histories that differ significantly from those seen in traditionally cast or wrought products, resulting in location-dependent microstructures and mechanical properties that also differ from traditional counterparts. I will discuss our work on elucidating and describing the relationships among processing, microstructure and mechanical properties in monolithic stainless steel and titanium alloys made by AM as well as functionally graded materials made by AM.
Bio: Allison Beese is an assistant professor of materials science and engineering at the Pennsylvania State University. Her research focuses on elucidating structure-mechanical-property relationships in materials, namely the effect of microstructure on large deformation, damage accumulation and fracture, toward the exploitation of current materials and the design of new materials. Her group performs unique multiaxial mechanical characterization of materials, develops physics-based models to describe the micromechanics of these materials, and performs computational simulations to describe and predict their mechanical behavior. She received her bachelor's degree in mechanical engineering from Penn State University, her master's degree and doctorate in mechanical engineering from MIT and was a postdoctoral fellow at Northwestern University prior to joining Penn State in 2013.