An integrated model for dendritic and planar interface growth and morphological transition in rapid solidification

摘要: Rapid solidification can be achieved by quenching a thin layer of molten metal on cold substrate, such as in melt spinning and thermal spray deposition. An integrated model is developed to predict microstructure formation rapidly solidified materials through substrate quenching. The solves heat mass diffusion equations together with moving interface that may either real solid/liquid or an artificial dendrite tip/melt interface. For the latter case, growth theory introduced at also transition morphology, e.g., from dendritic planar growth. Microstructure development Al-Cu alloy splats quenched copper investigated using model. Oscillatory predicted under critical range interfacial heat-transfer coefficient between splat substrate. Such oscillatory leads banded solute structure, which agrees linear stability analysis. Finally, selection map proposed for process based undercooling contact conditions