Date: July 2, 2026
Report title: microstructure and mechanical properties of additively manufactured alloys.
Reporting time: Wednesday, July 8, 2026, from 10: 00 am to 12: 00 am.
Informant: Upad Rasta Ramamurty (President's Chair Professor, School of Mechanical & Aerospace Engineering, Nanyang Technological University, Singapore).
Address: Room 303, Building 38, Wushan Campus, South China University of Technology
Organizer: School of Mechanical and Automotive Engineering
Brief introduction of the speaker:
Upadrasta Ramamurty is currently the President Professor of Nanyang Technological University in Singapore, the Chief Scientist of Singapore Science and Technology Research Council (A*STAR), the Fellow of Indian Academy of Sciences, the Fellow of Indian Academy of Engineering and the Fellow of World Academy of Sciences (TWAS). He received his doctorate from Brown University in 1994, and worked as a postdoctoral fellow at University of California-Santa Barbara and Massachusetts Institute of Technology from 1994 to 1997. From 1997 to 2018, he worked as an assistant professor, associate professor and professor at Nanyang Technological University in Singapore and Indian Institute of Science and Technology (Bangalore). Since 2018, he has served as the president professor at Nanyang Technological University. His research interests include the deformation and fracture behavior of amorphous and crystalline alloys, additive manufacturing and the development and application of nano-indentation technology. He has published 380 papers (h-index=91) in academic salons of internationally renowned journals, with more than 30,000 citations. He is currently the editor of Acta Materialia and Scripta Materialia. Won Scopus Young Scientist Award, TWAS Award, Metallurgist Award of the Year awarded by Indian Government, ShantiSwarup Bhatnagar Award, CNR Rao Lecture Award of Advanced Materials of Indian Institute of Materials Research and Li Xun Lecture Award of Institute of Metals, China Academy of Sciences.
Summary of report:
A detailed understanding of the correlations between the processing, microstructures, and mechanical performance of alloys is a must before they can be deployed for structural applications with a high degree of reliability. Such an understanding, which allows for tailoring of advanced alloys for the targeted performances, is well-established for those manufactured using the conventional route of manufacturing alloys. Moreover, there are several options available for tuning the microstructures in that route. However, some of them—especially microstructural tuning through the judicious selection of the thermo-mechanical processing steps—are not available in additive manufacturing (AM) of metallic components, which 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. and hence is being pursued with considerable scientific and technological vigor across the world. However, alloys made with AM techniques such as laser powder bed fusion (LPBF) have substantially finer microstructures (due to rapid solidification) and distinct mesoscale features. Consequently, their strength is often higher while the ductility is lower, vis-à-vis their conventionally manufactured counterparts. The meso-structural features, a result of the ‘bottom up’ approach of building components—line-by-line and layer-by-layer with in-situ alloying capability—can impart very high fracture toughness to these alloys. The presence of porosity, which is inevitable given that the feedstock is powder, results in lowered unnotched fatigue resistance. Implications of these in terms of possible directions for designing AM alloys with high mechanical performance will be discussed.
