TY - JOUR A1 - Vogel, F. A1 - Ngai, S. A1 - Zhou, X. Y. A1 - Zaiser, E. A1 - Manzoni, Anna Maria A1 - Wu, Y. A1 - Zheng, W. W. A1 - Zhang, P. A1 - Thompson, G. B. T1 - Tracking maze-like hierarchical phase separation behavior in a Fe-Si-V alloy JF - Journal of Alloys and Compounds N2 - Optimizing the properties of next-generation high-temperature and corrosion-resistant alloys is rooted in balancing structure-property relationships and phase chemistry. Here, we implement a complementary approach based on transmission electron microscopy (TEM) and atom probe tomography (APT) to ascertain aspects of hierarchical phase separation behavior, by understanding the microstructural evolution and the three-dimensional (3D) nanochemistry of a single crystal Fe79.5Si15.5V5.0 (at%) alloy. A maze-like hierarchical microstructure forms, in which a complex network of metastable disordered α plates (A2 phase) emerges within ordered α1 precipitates (D03 phase). The supersaturation in α1 (D03) precipitates with Fe and V drives the formation of α (A2) plates. The morphology of α (A2) plates is discussed concerning crystal structure, lattice misfit, and elastic strain. Phase compositions and a ternary phase diagram aid the thermodynamic assessment of the hierarchical phase separation mechanism via the Gibbs energy of mixing. A perspective on the stabilization of hierarchical microstructures beyond Fe79.5Si15.5V5.0 is elaborated by comparing hierarchical alloys. We find that the ratio of elastic anisotropy (Zener ratio) serves as a predictor of the hierarchical particles’ morphology. We suggest that the strengthening effect of hierarchical microstructures can be harnessed by improving the temporal and thermal stability of hierarchical particles. This can be achieved through phase-targeted alloying aiming at the hierarchical particles phase by considering the constituents partitioning behavior. Beyond Fe79.5Si15.5V5.0, our results demonstrate a potential pathway for improving the properties of high-temperature structural materials. KW - Atom probe tomography KW - Transmission electron microscopy KW - Hierarchical microstructure KW - Phase separation PY - 2023 DO - https://doi.org/10.1016/j.jallcom.2023.172157 SN - 0925-8388 VL - 968 SP - 1 EP - 17 PB - Elsevier B.V. AN - OPUS4-58343 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Manzoni, Anna Maria A1 - Haas, S. A1 - Kropf, H. A1 - Duarte, J. A1 - Cakir, Cafer Tufan A1 - Dubois, F. A1 - Többens, D. A1 - Glatzel, U. T1 - Temperature evolution of lattice misfit in Hf and Mo variations of the Al 10 Co 25 Cr 8 Fe 15 Ni 36 Ti 6 compositionally complex alloy JF - Scripta Materialia N2 - Misfits of γ- γ’ based Al10Co25Cr8Fe15Ni36Ti6 and its Mo- and Hf-variations are studied up to a temperature of 980 °C and compared with Ni- and Co-based superalloys. The trace elements decrease (Hf) or increase (Mo) the edge radii of the γ’ cuboids without changing their sizes. Atom probe measurements revealed that the Hf alloy prefers the γ’ phase while Mo prefers the γ matrix, leading to a lattice parameters enhancement of both phases, as could be revealed by synchrotron X-ray diffraction. The misfit is influenced in opposite ways: Hf increases the positive misfit, while Mo reduces it at all investigated temperatures. KW - Metal and alloys KW - Transmission electron microscopy KW - X-ray diffraction KW - Atom probe tomography KW - High entropy alloy PY - 2020 DO - https://doi.org/10.1016/j.scriptamat.2020.07.013 VL - 188 SP - 74 EP - 79 PB - Elsevier Ltd. AN - OPUS4-51025 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -