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MM: Fachverband Metall- und Materialphysik
MM 21: Phase Transformations II
MM 21.10: Vortrag
Mittwoch, 11. März 2026, 12:45–13:00, SCH/A215
Forming bicontinuous microstructures by distributed internal melting at the Ni3Sn4 peritectic — •Zhongyang Li1, Lukas Lührs1, and Jörg Weissmüller1,2 — 1Institute of Materials Physics and Technology, Hamburg University of Technology, Hamburg — 2Institute of Hydrogen Technology, Helmholtz-Zentrum Hereon, Geesthacht, Germany
A recent study on peritectic melting of TiAg suggests that a bicontinuous structure can be obtained through liquid film migration (LFM) during annealing. Without the requirement of mass exchange with the environment, peritectic melting is free of the restrictions on sample size. To date, application of this method is limited to TiAg. In this work, the intermetallic compound Ni3Sn4 is selected as the new parent system for peritectic melting. After annealing and quenching, spherical clusters are obtained, consisting of crystallographically aligned Ni3Sn2 ligaments and interpenetrating Sn phase. The phase decomposition proceeds via the LFM mechanism, i.e. complete melting of Ni3Sn4 and growth of Ni3Sn2 across the melt layer. Constitutional supercooling, induced by a composition gradient within the melt, promotes cellular growth of Ni3Sn2 nuclei, resulting in a ligament structure. Based on previous studies on peritectic and partial melting, we propose the concept of distributed internal melting, which utilizes the internal pre-melting sites (vacancies, dislocations and grain boundaries) to initiate LFM and generates bicontinuous structures through heat treatment.
Keywords: Liquid-metal dealloying; Peritectic melting; Liquid film migration; NiSn alloy; Constitutional supercooling