COMPUTATIONAL MODELING OF PARTIAL PHASE CHANGE IN THE HYPOEUTECTIC BINARY ALLOY Al–7Si MELT OVER A COOLED TILTED PLATE

A computational model has been developed to study the eff ect of the tilt angle (15, 30, 45, and 60^o ) and pouring temperature (893, 903, 913, and 923 K ) on the phase change behavior of the hypoeutectic binary alloy Al–7Si. The analysis has been done with the help of the obtained temperature fi eld, solid fraction evolution, as well as the Si distribution and macrosegregation. The two-dimensional multiphase volume-averaging transient model is used for computational modeling, incorporating phase diagram information, enthalpy-updating scheme, composition–solid fraction coupling, and variation in the thermophysical properties inside a mushy zone. It is observed that the eff ect of the tilt angle on the cooling rate is much superior to the pouring temperature eff ect. Moreover, the formation of eutectic plateau and negative macrosegregation are observed near the surface of the tilted plate in the eutectic temperature zone. Negative macrosegregation becomes high near the exit of the tilted surface.
   
Author:  Rishitosh Ranjan, P. Ghose, B. Surekha
Keywords:  hypoeutectic binary alloy, phase change, cooled tilted plate, semisolid metal processing
Page:  350