2024 IRG-1: Discovery of Ni Activated Sintering of MoNbTaW Guided by a Computed Grain Boundary “Phase” Diagram
•In IRG-1, Luo, Xin, Rupert, and their students have discovered Ni activated sintering of MoNbTaW guided by a computed grain boundary “phase” (complexion) diagram.
•This collaborative study made the first observation of solid-state activated sintering in a high-entropy alloy.
•Grain boundary (GB) wetting was observed above the solidus line, implying subsolidus GB prewetting to promote sintering.
•A GB l diagram was computed to forecast high-temperature GB disordering and explain activated sintering.
•Scanning transmission electron microscopy revealed only weak Ni segregation in furnace-cooled specimens, suggesting GB drying during cooling that may alleviate GB embrittlement.
S. Shivakumar, K. Song, C. Wang, T. Lei, H.L. Xin, T.J. Rupert, J. Luo “Discovery of Ni Activated Sintering of MoNbTaW Predicted by a Computed Grain Boundary Diagram” Scripta Materialia, 239, 115777 (2024) https://doi.org/10.1016/j.scriptamat.2023.115777
S. Shivakumar, K. Song, J. Luo (University of California, San Diego)
C. Wang, T. Lei, H.L. Xin, T.J. Rupert (University of California, Irvine)