The microstructure development during a cooling period of alloys being immiscible in the liquid state such as Al-Pb or AI-Bi has gained renewed scientific and technical interest during the last decades. Experiments ha...The microstructure development during a cooling period of alloys being immiscible in the liquid state such as Al-Pb or AI-Bi has gained renewed scientific and technical interest during the last decades. Experiments have been performed to investigate the phase transformation kinetics in the liquid miscibility gap and numerical models have been developed to simulate and analyze the solidification process. The recently developed computational modeling techniques can, to some extent, be applied to describe the decomposition, the spatial phase separation and the microstructure evolution during a cooling period of an immiscible alloy through the miscibility gap. This article overviews the researches in this field.展开更多
Modeling and simulation have been carried out for Al-Pb alloys to investigate the Brownian coagulation effect on the microstructure development in a gas-atomized drop during the liquid-liquid decomposition. The result...Modeling and simulation have been carried out for Al-Pb alloys to investigate the Brownian coagulation effect on the microstructure development in a gas-atomized drop during the liquid-liquid decomposition. The results indicate that Brownian coagulation has a weak effect on the nucleation and a relatively strong effect on coarsening the minority phase droplets. The influence of Brownian coagulation on the liquid-liquid decomposition decreases with the increase in the diameter （or the decrease in the cooling rate） of the atomized drop.展开更多
A numerical model is presented describing the microstructure evolution of an immiscible alloy under the continuous casting conditions. Calculations are carried out to investigate the microstructure evolution in a vert...A numerical model is presented describing the microstructure evolution of an immiscible alloy under the continuous casting conditions. Calculations are carried out to investigate the microstructure evolution in a vertical strip cast sample of Al+5wt pct Pb alloy. The numerical results show that there exists a peak value for the supersaturation in front of the solid祃iquid interface, and the minority phase droplets are nucleated in a region around this peak. Under strip casting conditions the Marangoni migration dominates the motion of droplets. This leads to an accumulation of the minority phase droplets in front of the solid祃iquid interface.展开更多
文摘The microstructure development during a cooling period of alloys being immiscible in the liquid state such as Al-Pb or AI-Bi has gained renewed scientific and technical interest during the last decades. Experiments have been performed to investigate the phase transformation kinetics in the liquid miscibility gap and numerical models have been developed to simulate and analyze the solidification process. The recently developed computational modeling techniques can, to some extent, be applied to describe the decomposition, the spatial phase separation and the microstructure evolution during a cooling period of an immiscible alloy through the miscibility gap. This article overviews the researches in this field.
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation （NNSF） of China and the International Cooperation Key Project of NNSF of China （Nos. 50395104, 50271076 and 50371092）the Natural Science Foundation of Liaoning Province （20050047）.
文摘Modeling and simulation have been carried out for Al-Pb alloys to investigate the Brownian coagulation effect on the microstructure development in a gas-atomized drop during the liquid-liquid decomposition. The results indicate that Brownian coagulation has a weak effect on the nucleation and a relatively strong effect on coarsening the minority phase droplets. The influence of Brownian coagulation on the liquid-liquid decomposition decreases with the increase in the diameter （or the decrease in the cooling rate） of the atomized drop.
文摘A numerical model is presented describing the microstructure evolution of an immiscible alloy under the continuous casting conditions. Calculations are carried out to investigate the microstructure evolution in a vertical strip cast sample of Al+5wt pct Pb alloy. The numerical results show that there exists a peak value for the supersaturation in front of the solid祃iquid interface, and the minority phase droplets are nucleated in a region around this peak. Under strip casting conditions the Marangoni migration dominates the motion of droplets. This leads to an accumulation of the minority phase droplets in front of the solid祃iquid interface.
