报告题目StructuralIntegrity of 3DPrintedMetals

报告人Upadrasta Ramamurty院士 （新加坡南洋理工大学）

会议时间 2022/1/13 19:30（北京时间）

腾讯会议 880 702 750

Abstract:Additive manufacturing (AM) of metallic components offers a number of technological advantages such as near-net shape forming using a single processing step, flexible and on-demand manufacturing, near-zero material loss during fabrication, etc. Additionally, alloys made with AM techniques such as selective laser (SLM) have substantially finer microstructures (due to rapid solidification) and distinct mesoscale features. A synergetic interplay between these micro- and meso-structural features leads to high strength – toughness combinations. However, certain other intrinsic features such as microporosity can adversely affect the fatigue resistance in SLM alloys. In contrast, the fatigue strength (σ_f) of binder jet printed 316L austenitic stainless steel, which contain significant amounts of pores, are surprisingly comparable to those of the conventionally manufactured 316L whereas the SLM specimens are far inferior in terms ofσ_falthough the porosity in them is relatively smaller. All these results are rationalized by recourse to the distinct microstructures of additively manufactured alloys and how they affect plasticity and crack growth. Implications of these results in terms of possible directions for designing AM alloys with high mechanical performance will be discussed.

Biography: After obtaining a PhD degree from Brown University and post-doctoral stints at UCSB and MIT, Ramamurty held faculty positions at NTU and IISc, before returning to NTU in 2018 where he currently holds a President's Chair Professor position. His current research interests include deformation and fracture behavior of amorphous as well as crystalline alloys, additive manufacturing, and the development and application of the nanoindentation technique. He published 315 papers in peer reviewed international journals and is an editor of Acta Materialia and Scripta Materialia. He is an elected Fellow of both the National Academies of Engineering and Sciences of India, and TWAS-The World Academy of Sciences, and is a recipient of the Scopus Young Scientist and National Metallurgist Day awards, Shanti Swarup Bhatnagar and TWAS prizes (both in Engineering Sciences category), and Swarnajayanthi and JC Bose National Fellowships. He delivered the CNR Rao Prize Lecture in Advanced Materials of the Materials Research Society of India and the Lee Hsun Award Lecture of IMR, Chinese Academy of Sciences. He is an Honorary Professor at the International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research, India and Qiushi Distinguished Visiting Professor of Zhejiang University, China.