报告题目一：Micro Laser Powder Bed Fusion: Process, Materials and Applications

时间：2025年12月08日（星期一）14:00-16:00

会议地点：腾讯会议：201-850-900，密码：654321

报告人：SONG Xu

邀请人：李桂伟

报告人简介：

Prof obtained his Bachelor degree from Tsinghua University, Beijing in Mechanical and Automation Engineering in 2006 and Doctorate degree from University of Oxford, UK in Material Engineering in 2010. After working two years as postdoctoral RA in Rolls-Royce University Technology Center (RR-UTC) Oxford on the residual stress analysis of different manufacturing processes, he joined SIMTech, A*STAR as a research scientist from 2012 and was promoted to senior scientist in 2019), working on various micrometal processing techniques, notably micro forming and micro selective laser melting. He joined the Chinese University of Hong Kong in 2019 as Assistant Professor and was promoted to tenured Associate Professor in 2025, conducting research and teaching in the area of high-precision laser powder bed fusion process and design for additive manufacturing. He has published more than 100 journal papers on the topic of material deformation and manufacturing processes, and is listed in World’s Top 2% Scientists by Stanford University/Elsevier from year 2023 onwards. His recent work on high-precision laser powder bed fusion process has led to many publications, such as Nature Communications and Science Advances, as well as industry awards, such as the Red Dot Design Award and Inventions Geneva Gold Medal, etc. He currently serves as the editor-in-chief of the journal <Materials and Design> (IF=7.9) and interim editor-in-chief of the journal <Materials Today Advances> (IF=8.0).

摘要

Micro laser powder bed fusion (µLPBF) technology offers great potentials to 3D printing research community, as it enables fabrication of complex metallic components with greater accuracy and better properties. By comprehensively comparing the µLPBF with conventional LPBF, it is found that better surface finish, finer microstructure, more desirable mechanical properties and smaller distortion can be obtained by µLPBF. Moreover, due to higher energy-volume-density than the conventional LPBF process, µLPBF is capable to fabricate highly reflective materials, such as pure copper, while maintaining low laser power, high resolution and good material properties. The µLPBF combining fine beam and small layer thickness managed to achieve the enhanced strength and ductility for the printed pure copper, while keeping the thermal and electrical conductivity close to the annealed one without heat treatment. To further push the printing resolution of pure copper to less than 100 µm and further reduce the surface roughness to less than 1 µm, we propose a facile oxide-dispersion-strengthening (ODS) strategy that enables AM of Cu with sub-100 μm (~70 μm) resolution by laser powder-bed fusion (PBF-LB). This ODS strategy starts with oxygen-assisted gas atomization (OAGA) to introduce ultrafine and well-dispersed Cu2O nanoparticles into the pure Cu powder feedstock. These nanoscale dispersoids not only improve the laser absorptivity and the viscosity of the melt, but also promote dynamic wetting behaviour, resulting in a low-enthalpy keyhole mode during printing and stabilization of the melt pool. The additively manufactured (AMed) ODS Cu exhibits a remarkable yield strength of ~450 MPa and a large uniform elongation of ~12%, while preserving a high electrical conductivity. The superb sub-100 μm printing resolution, paired with the excellent mechanical and electrical properties of our AMed ODS Cu, offers great opportunities to develop next-generation Cu micro\u0002architected devices for functional applications. As an example, we printed the first-ever ODS Cu micro-architected terahertz antenna, which demonstrates a 2.5-fold improvement in signal intensity compared with traditional 3D\u0002printed pure Cu antennas.

报告题目二：High-fidelity Modeling of Multi-Material Additive Manufacturing: Process, Microstructure, and Property

时间：2025年12月9日（星期二）19:00-21:00

会议地点：腾讯会议：248-968-711，密码：58823

报告人：Wentao Yan

邀请人：李桂伟

报告人简介：

Dr. Wentao Yan is an associate professor in the Department of Mechanical Engineering, National University of Singapore (NUS). Before joining NUS in 2018, Dr. Yan was a postdoctoral fellow at Northwestern University and also a guest researcher at the National Institute of Standards and Technology in the USA. He received his Ph.D. degree jointly at Tsinghua University, Beijing and Northwestern University, USA. He got his Bachelor degree from the Department of Mechanical Engineering, Tsinghua University, Beijing in 2012. Supported by multi-million grants, his research group with 20+ students focus on multi-scale multi-physics modeling, experimental investigation and data analysis of additive manufacturing. ~30 of his former postdocs and PhD students have got faculty positions. He has published >150 papers on flagship journals, such as Nature Communications, Acta Materialia, JMPS and CMAME, which have received over 9000 citations. His team was the biggest winner in the 2022 NIST AM-Bench Simulation Challenges by winning 9 awards in the total 25 tests (totally 40 awards were presented). He has won multiple best paper awards in various journals. He currently serves as the Senior Editor for Additive Manufacturing Journal and an editorial board member for IJMTM and Materials & Design.

报告摘要：

Multi-material additive manufacturing opens a new avenue for materials design and synthesis, but also increases the complexity in the process-structure-property relationships. To this end, we have developed and seamlessly integrated a series of high-fidelity multi-physics models for multi-material additive manufacturing. Specifically, multiphase flow models using the coupled computational fluid dynamics (CFD) and discrete element method (DEM) simulate the motions of unmelted powder particles in the melting procedure of nano- and micro-particle reinforced composites. For the cases where different powders are melted for in-situ alloying, the model incorporates the major physical factors, e.g., the composition evolution due to evaporation and convection, the varying thermo-physical material properties dependent on the local chemical compositions, and the heat release/absorption due to alloying/chemical reactions. The microstructure evolutions at both the grain- and dendrite- scales are modelled using the phase field and cellular automaton methods. The mechanical properties and thermal stresses are simulated using the crystal plasticity finite element (FE) model, which incorporates the realistic geometry (rough surfaces and voids), temperature profiles and microstructures including the interactions between reinforcing particles and dislocations. These models have proven to be useful in revealing the physical mechanisms and guiding manufacturing process optimization, which have been validated against experiments.

报告题目三：Additive Manufacturing of Metals: From Complex Alloys to Simple Alloys

时间：2025年12月11日（星期四）9:00-11:00

会议地点：腾讯会议：573-308-810，密码：645327

报告人：Wen Chen

邀请人：李桂伟

报告人简介：

Dr. Wen Chen is an Associate Professor in the Department of Aerospace and Mechanical Engineering at the University of Southern California (USC). Before joining USC in Jan 2025, he was an Associate Professor in the Department of Mechanical and Industrial Engineering at the University of Massachusetts Amherst. He earned a B.S. in Materials Science and Engineering from Nanjing University of Science and Technology (2008), an M.Phil in Industrial and Systems Engineering from The Hong Kong Polytechnic University (2011), and a Ph.D. in Mechanical Engineering and Materials Science from Yale University (2015), followed by postdoctoral research at Lawrence Livermore National Laboratory. His research spans advanced manufacturing, mechanical behavior of materials, physical metallurgy, and architected materials. He has received the NSF CAREER Award, SME Outstanding Young Manufacturing Engineer Award, TMS Young Professional Leaders Award, and the Barbara H. and Joseph I. Goldstein Outstanding Junior Faculty Award. He serves as an Associate Editor for Materials Futures. Dr. Chen holds 6 U.S. patents and has published more than 100 papers in leading journals, including Nature, Nature Materials, Nature Communications, and Science Advances. In 2023, he was recognized by the journal Matter as a rising star in materials science.

报告摘要：

The growing demand for materials that operate in extreme environments is driving the development of metal alloys with increasingly complex chemistries. However, synthesis and processing of complex alloys via conventional routes are challenging. Additive manufacturing, also called 3D printing, is a disruptive technology for creating materials and components in a single print. Harnessing the vast compositional space of complex alloys and the far-from-equilibrium processing conditions (e.g., large thermal gradients and high cooling rates) of additive manufacturing provides a paradigm-shifting pathway for material design. In this talk, I will present the potential of utilizing laser additive manufacturing and direct ink writing to produce metal alloys with engineered structural hierarchy across multiple length scales. These unique microstructures give rise to exceptional mechanical and functional properties that extend far beyond those accessible by conventional manufacturing. In addition, I will discuss the abundant opportunities enabled by additive manufacturing for high-throughput materials discovery and design of alloys with reduced compositional complexity toward sustainable metallurgy.