The microscopy and composition of quenched solid-liquid interfaces

摘要: Abstract Microstructures and composition variations are described at quenched planar or cellular solid-liquid fronts in A1–2 wt% Cu. Steady state solute profiles obtained different freezing rates from the liquid self consistent correspond to a diffusion coefficient of ∼ 3 × 10 -5 cm 2 / sec . Interfacial concentrations also compatible with relevant equilibrium diagram. Transient peaks high copper content occur immediate vicinity sharp transitions between dendritic morphologies. The spacings initial products quenching (cells dendrites) seem be determined during operation do not change subsequent growth. It is suggested that spacing represents wave length successful perturbations steady fronts, dendrite subsequently (a) because growth velocity sensitive function this spacing, (b) crystallographic restrictions prevent gradual adjustment A possible relevance these results structure castings noted.