Observations on the numerical prediction of the columnar to equiaxed grain transition in castings

The two approaches that have been made to the study of the columnar to equiaxed grain transition (CET) in castings using numerical computer models are considered. The first involves modelling the simultaneous growth of columnar and equiaxed grains. The second employs a simple macroscopic model of heat transfer and columnar solidification to predict the values of certain parameters at CET interfaces observed in experimentally solidified alloys. This paper questions conclusions that have been reported by researchers from a study employing the second approach and, also, the validity of the approach as a means of obtaining meaningful data on the CET.