Dynamic Localization Effect of Dendritic and Eutectic Growth Patterns Stimulated by Space Fluid Flow

Abstract

Abstract Conventional solidification theory asserts that eutectic phases solidify into only one specific morphology at a fixed undercooling when volume effects are negligible, while dendrites adopt rotationally parabolic tips. Here, experiments aboard China Space Station reveal that space fluid flow localization reshapes these dynamics: confined solute‐thermal coupling near solid‐liquid interfaces drives transitions among three eutectic growth patterns (worm‐like, lamellar, faceted). Simultaneously, Marangoni convection at large undercoolings induces non‐parabolic dendritic tip morphologies (dome‐like, finger‐like, needle‐like). Spatially ordered separation of eutectic and dendritic zones is governed by localized spherically symmetric temperature and concentration fields arising from space fluid flow, whereas buoyancy‐driven convection in terrestrial gravity environment disrupts this ordering, perturbing phase domain distributions. When solidified at a small undercooling, the weak convection during late stage preserves the near‐perfect symmetry of dendrites under microgravity. These findings uncover novel dendritic and eutectic growth patterns under microgravity and may be applied to in‐situ space manufacturing and controlled growth of crystals.