On December 15, 2025, Assistant Prof. Dr. Shao-Pu Tsai(蔡劭璞), Department of Materials Science and Engineering, National Taiwan
University, Taiwan, gave a lecture at NIMS as the 181st Structural Materials Seminar.
Date and Time:Monday, Dec. 15, 2025. 11:00～12:00
Location: Conference Room, 5th Floor, Advanced Structural Materials Building, NIMS Sengen Site
Title: Additively manufactured sustainable 8xxx series aluminum alloys
Chair：Seiichiro II, Microstructure Analysis Group
Dr. Shao-Pu Tsai (2nd from right)
Abstract:
The deleterious influence of iron on recycled cast aluminum alloys has historically constrained their applicability within the metallurgical community. This investigation leverages powder metallurgy routes, specifically the transformation of recycled aluminum alloys into powders followed by net-shape fabrication via laser-powder bed fusion (L-PBF), to overcome limitations associated with conventional casting. Fe-containing aluminum alloys were systematically processed by L-PBF, with their microstructural evolution elucidated through in-situ heating transmission electron microscopy (TEM). High-temperature tensile testing was conducted to ascertain the alloys’ mechanical responses under thermal stress. The analyses demonstrate the presence of precipitate embryos within the cellular microstructure of as-built specimens, which manifest significant coarsening and dissolution concomitant with cellular structure breakdown above 325 °C. This thermal regime corresponds with a pronounced deterioration in mechanical properties, indicating a critical threshold for high-temperature performance in additively manufactured, Fe-bearing aluminum alloys.