Effect of tiny amount of impurity and convective transport on dendrite growth kinetics

摘要

Using the developed sharp-interface model of solidification we quantitatively estimate influence of tiny amount of impurity and forced convection on kinetics of dendritic growth. As tested systems, we choose Ni and Ni–Zr dendrites which are growing into a stagnant undercooled melt, the melt with incoming forced flow and with/without impurity (that is small amount of Zr diluted in a pure Ni). The model predictions and comparisons allow us to quantitatively estimate predominant influence of impurity (chemical segregation), thermal influence (due to temperature inhomogeneity) and hydrodynamic effects (due to investigated laminar and forced melt flow) on the dendrite growth kinetics.