Analysis for Free Dendritic Growth Model Applicable to Nondilute Alloys

A steady-state free dendritic growth model applicable to concentrated alloys was proposed as an extension of Wang et al.’s model.[14] The present model adopted a realistic thermodynamic model to replace the Baker–Cahn equation and included a generalized marginal stability criterion and a nondilute solute trapping model to completely eliminate the dilute alloy limitation. Comparative analysis shows that Wang et al.’s model is a very close approximation to the present model at low undercoolings for dilute alloys. However, the difference appears at high undercoolings even for dilute alloys. Furthermore, the difference of the model predictions for both models increases with nominal composition of alloys due to the inherent limitation of dilute alloys in Wang et al.’s model. A comparison with the experimental data for Cu₇₀Ni₃₀ alloy demonstrates the applicability of the present model to nondilute alloys.