材料期刊网

A model is developed to analyze the microstructure evolution in a continuously solidified hypermonotectic alloy. The model takes into account the common actions of the nucleation and diffusional growth/shrinkage of the minority phase droplets, the spatial phase segregation, and the convections of the melt. The microstructure formation in a continuously solidified hypermonotectic alloy is calculated. The numerical results demonstrate that the convections have great effect on the microstructure formation. The convective flow against the solidification direction causes an increase in the nucleation rate while the convective flow along the solidification direction causes a decrease in the nucleation rate of the minority phase droplets. The convections lead to a more nonuniform distribution of the minority phase droplets in the melt. It causes an increase in the size of the largest minority phase droplets and is against the obtaining of the hypermonotectic alloys with a well-dispersed microstructure.