Li, ZhongyangZhongyangLiLührs, LukasLukasLührsWeissmüller, JörgJörgWeissmüller2026-03-052026-03-052026-02-23Journal of Materials Research and Technology 41: 6202-6210 (2026)https://hdl.handle.net/11420/61877Guided by a current interest in processing schemes, such as liquid-metal dealloying, providing fine-scale bicontinuous metal microstructures, we investigate the microstructure evolution during the peritectic melting of Ni₃Sn₄. The product microstructure is an interconnected array of spherical clusters of crystallographically aligned Ni₃Sn₂ ligaments, interpenetrated by a contiguous liquid phase. When quenched to room temperature, the prevalent microstructure consists of two interpenetrating solid phases. Leaching the solidified Sn melt produces monolithic porous bodies of Ni₃Sn₂. The characteristic structure size can reach down to 2 μm, a microstructure refinement by almost 2 orders of magnitude as compared to the 150 μm grain size of the master alloy. Remarkably, a more severe refinement is achieved at higher annealing temperatures. Our experiments identify liquid-film migration as the controlling process, here concurrent with constitutional supercooling and cellular solidification. We argue that peritectic melting exemplifies a more general family of processes of distributed internal melting (DIM). These processes exploit the abundant nucleation of regions of melt, finely distributed throughout a parent microstructure, when the alloy is heated into a two-phase solid–liquid regime of its phase diagram. DIM provides a novel and versatile pathway to fine-scale bicontinuous microstructures.en2214-0697202662026210Elsevierhttps://creativecommons.org/licenses/by/4.0/Constitutional supercoolingLiquid film migrationLiquid-metal dealloyingNiSn alloyPeritectic meltingTechnology::620: Engineering::620.1: Engineering Mechanics and Materials Science::620.11: Engineering MaterialsJournal Articlehttps://doi.org/10.15480/882.1681510.1016/j.jmrt.2026.02.18910.15480/882.16815Journal Article