Effect of cooling rate on eutectic constituent and solid solubility of Al-6Cu alloy

The ingots of Al-6Cu alloy were prepared by the wedge-shaped copper mode casting with the cooling rates of 2 K/s, 10 K/s, 25 K/s and 100 K/s to explore the effect of cooling rate on the area fraction of eutectic constituent, alpha-Al lattice parameter and relative solid solubility. The experimental results revealed that when the cooling rate rose from 2 K/s to 10 K/s, the area fraction of the eutectic constituent and the lattice parameter of alpha-Al decelerated, but the relative solid solubility of alpha-Al increased. When the cooling rate continued to reach 100 K/s, the area fraction of the eutectic constituent and the alpha-Al lattice parameter elevated, lowering the alpha-Al relative solid solubility. According to the model of non-diffusion of solid phase and incomplete mixed solidification of a liquid phase, as for Al-6Cu alloy, relative solid solubility initially increases and then decreases with a boost in cooling rate. The model results are consistent with the experimental results.