Dendritic Growth in an Aluminum-Silicon Alloy

Unidirectional solidification experiments have been carried out on an Al-3 wt.% Si alloy as a function of temperature gradient, G and growth rate, V. The samples were solidified under steady-state conditions with a constant growth rate of 8.20 μm/s at different temperature gradients (1.97-6.84 K/mm) and with a constant temperature gradient (6.84 K/mm) at different growth rates (8.20-492.76 μm/s). Microstructure parameters (primary dendrite arm spacing, λ1, secondary dendrite arm spacing, λ2, dendrite tip radius, R and mushy zone depth, d) were measured as a function of temperature gradient and growth rate. The experimental results have been compared with the current theoretical models and similar experimental works.