Model for calculation of microstructural
development in rapidly directionally solidified immiscible alloys
development in rapidly directionally solidified immiscible alloys
(Institute of Metal Research, The Chinese Academy of Sciences,
Shenyang 110016, China)
Shenyang 110016, China)
Abstract: A model has been developed for the calculation of the microstructural evolution in a rapidly directionally solidified immiscible alloy. Numerical solutions have been performed for Al-Pb immiscible alloys. The results demonstrate that at a higher solidification velocity a constitutional supercooling region appears in front of the solid/liquid interface and the liquid-liquid decomposition takes place in this region. A higher solidification velocity leads to a higher nucleation rate and, therefore, a higher number density of the minority phase droplets. As a result, the average radius of droplets in the melt at the solid/liquid interface decreases with the solidification velocity.
Key words: immiscible alloy; directional solidification; microstructure; theory and modeling