Dr. Yinmin (Morris) Wang, Professor of Materials Science and Engineering at University of California, Los Angeles, will give a seminar titled "Additive Manufacturing High-Strength and High-Ductility Structural Materials" to the interested faculty and students at Discovery Park.

Abstract

The rising influences of additive manufacturing (AM, aka 3D printing) on various industries have propelled materials scientists and mechanical engineers to search for the exotic materials properties that can be created by these techniques. Specially, laser powder-bed-fusion (L-PBF) involves extreme processing conditions that allow for opportunities to create materials with both high strength and high ductility. This talk will present my group effort in the recent decade to investigate the strength and ductility of several model materials systems, including pure copper, 316L stainless steel, and medium entropy alloys. All these materials were fabricated by L-PBF, which is one of the popular AM techniques to manufacture structural metals. In all these cases, we observe a hierarchical microstructure and multiple length scales that render a myriad of strengthening mechanisms. These interesting microstructures include solidification enabled cellular structures, low-angle grain boundaries, stack faults, and dense dislocations. High uniform tensile elongation is often observed in many cases due to the progressive work-hardening mechanisms triggered by these hierarchically heterogeneous microstructures. However, the highly nonconventional microstructures created by AM techniques impose tremendous challenges to decipher the strength scaling law and other materials properties. We will further elaborate the influence of residual stresses and other defects (such as pores) on mechanical behavior.

Biography

Yinmin (Morris) Wang is a professor of Materials Science and Engineering at University of California, Los Angeles. He joined UCLA as a full professor in 2020 after spending 17 years at Lawrence Livermore National Laboratory, where he was the inaugural recipient of Harold Graboske Fellowship in 2004 after obtaining his PhD and two master’s degrees (the Johns Hopkins University). His group research interest covers the structure-property relationship of additively manufactured metals, mechanics of nanostructured materials, and lithium-ion batteries. Prof. Wang is a Fellow of American Physical Society (elected in 2014) and a winner of several noticeable awards, including Nano50 Innovator Award and Frost & Sullivan Emerging Technology of the Year Award. He has served as an Editorial Board Member of Scientific Report from 2017-2020.