报告题目：Printability and performance of additively manufactured metals

报  告 人：Prof. Yinmin (Morris) Wang

报告时间：2024年07月10日（星期三）14:30

报告地点：河海大学常州校区56栋429

邀  请 人：赵永好教授

主办单位：材料科学与工程学院

欢迎广大师生参加！

报告人简介：

 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 multiple Director’s Science & Technology Awards at LLNL. He has served as an Editorial Board Member of Scientific Report from 2017-2020.

报告摘要：

 Additive manufacturing (AKA 3D printing) has attracted increasing attention recently due to its ability to produce complex geometry components with exotic materials properties that are unachievable via conventional manufacturing techniques. One unexpected challenge is, however, that many structural materials are difficult to print due to extreme processing conditions associated with 3D printing. Laser powder-bed-fusion, for example, involves processes that have ultrafast cooling rate and large temperature gradient, causing microcracks for many high-strength materials. This talk will present my group recent effort to investigate the printability of pure tungsten – one of the toughest materials for 3D printing. We will discuss step-by-step how the printability issue can be tackled. The second part of my talk will briefly discuss the performance (strength and ductility) of several model FCC materials, including 316L stainless steel and medium entropy alloys. These materials were fabricated by L-PBF. In all these cases, we observe a hierarchical microstructure and multiple length scales that help to promote a myriad of strengthening mechanisms. These interesting microstructures include solidification cellular structures, low-angle grain boundaries, stack faults, and dense dislocations. High uniform tensile elongation is often achievable in many cases due to the progressive work-hardening mechanisms triggered by these hierarchically heterogeneous microstructures. Nevertheless, the highly unconventional microstructures created by L-PBF impose tremendous challenges to decipher the strength scaling law and other materials properties.