EXTENSION OF THE CONTINUUM MODEL FOR TRANSPORT PHENOMENA OCCURRING DURING METAL ALLOY SOLIDIFICATION .2. MICROSCOPIC CONSIDERATIONS

In a companion paper, a continuum model for simulating transport pheno mena occurring during solidification of a binary metal alloy is extend ed to allow for treatment of effects such as solutal undercooling and solid transport in the form of floating and settling crystals. However , inclusion of such features requires auxiliary models which, in large part, depend on microscopic considerations. Such models are developed in this study and specifically deal with relations for solid and liqu id velocities under conditions involving solid motion, as well as dete rmination of solutal undercooling as a function of the solidification rate and stereological characteristics of the solid/liquid interface. The models also permit determination of final grain density and size.