APPLICATION OF LUKAS PHASE-DIAGRAM PROGRAMS TO SOLIDIFICATION CALCULATIONS OF MULTICOMPONENT ALLOYS

A multicomponent thermodynamic calculation of the phase boundaries bet ween liquid and various solid phases has been applied to the analysis of solidification problems for commercial alloys. The thermodynamic ca lculation was directly linked to micromodel codes which analyze the tr ansport of solute in the phases using various diffusion models, This a pproach treats the temperature and/or concentration dependence of part ition coefficients and liquidus slopes and of the formation of seconda ry solid phases, factors that are often neglected in solidification an alysis, With an accurate set of thermodynamic parameters, analysis can be performed for alloys of the same base metal but with different lev els of alloying agents. Calculations are presented for a Scheil model and for models that include solid diffusion and diffusion in the liqui d at the dendrite tip.