Dresden 2026 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 11: Structurally and Chemically Complex Alloys

MM 11.1: Vortrag

Dienstag, 10. März 2026, 10:15–10:30, SCH/A215

Quantifying chemical short-range order in Ti–Zr–Nb alloys — Yujun Zhao^1,2, Andrea Fantin³, Yue Li¹, Tong Li², and •Yilun Gong⁴ — ¹Max-Planck-Institut für Nachhaltige Materialien, Düsseldorf, Germany — ²Ruhr Universität Bochum (RUB), Bochum, Germany — ³Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany — ⁴University of Oxford, Oxford, UK

Chemical short-range order (CSRO) is expected to influence phase stability and defect interactions in Ti–Zr–Nb alloys, yet its direct quantification in equiatomic TiZrNb has remained unresolved. Here, we apply X-ray absorption spectroscopy (XAS) and X-ray pair-distribution-function (PDF) analysis to experimentally probe local chemical environments in single-phase bcc TiZrNb. Nanometre-scale compositional fluctuations and elemental pair distributions are further explored using orientation-specified atom-probe tomography (APT). XAS and PDF measurements reveal small but systematic local distortions in element-specific partial coordination shells (from XAS), consistent with emerging CSRO, and ensemble-averaged structural distortions in the atomic network (from PDF). To interpret these findings, we develop density functional theory-trained interatomic potentials and perform on-lattice Monte Carlo simulations to obtain the temperature-dependent equilibrium CSRO pair correlations. Together, these results provide the first quantitative CSRO map for TiZrNb, capturing its temperature and crystallographic dependence. This establishes TiZrNb as a reference system for understanding how CSRO influences phase stability, interstitial accommodation, and mechanical behaviour in refractory alloys.

Keywords: chemical short-range ordering; atom probe tomography; X-ray absorption spectroscopy; X-ray pair-distribution-function analysis; atomistic simulation