Topic: Mechanical and corrosion properties of stainless steels additively manufactured using the binder jet printing technique

Speaker: Prof. Upadrasta Ramamurty

             President' s Chair Professor, School of Mechanical and Aerospace Engineering
             Nanyang Technological University, Singapore

Time: 10:00-12:00, (Thur.) May 22^nd, 2025

Venue: Room 468, Lee Hsun Building, IMR CAS

Abstract:

Currently, there is considerable scientific as well as technological interest in additive manufacturing (AM) of alloys. The lion’s share of the research work has been on techniques such as the laser powder bed fusion (LPBF). Binder jet printing (BJP)—in spite of being relatively less expensive—has not received as much attention. In the recent past, we have investigated the microstructures, mechanical properties (including fatigue and fracture responses), and corrosion and stress corrosion cracking resistances of two common stainless steels (316L and 17-4 PH) that are produced using the BJP technique, and compared them with those produced using conventional manufacturing (casting followed by high temperature thermo-mechanical processing) and the LPBF techniques. In general, the porosity levels in the as-sintered BJP alloys tend to be relatively high, which mandates the additional post-processing step of hot isostatic pressing (HIP). Our studies also include HIP samples, to critically ascertain its utility. Many of the results are surprising and belie the expectations from the conventional and well-established structure – property correlations. I shall describe them in this talk, with the hope to enthuse interested researcher to pursue the BJP alloys.

Brief biography of the speaker:

Professor Upadrasta Ramamurty is the President’s Chair Professor in Mechanical and Aerospace Engineering and Materials Science and Engineering, in the School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore. He obtained a PhD degree in 1994 from Brown University, USA under the supervision of Professor Subra Suresh and did post-doctoral work at the University of California – Santa Barbara and the Massachusetts Institute of Technology. He held faculty positions at the Nanyang Technological University, Singapore and the Indian Institute of Science, Bangalore, India, before returning to NTU in 2018. His research interests include deformation and fracture behaviour of amorphous as well as crystalline alloys, additive manufacturing, and the development and application of the nanoindentation technique. He published 410 papers in peer reviewed international journals (~29,000 citations with a current h-index of 89) 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.