LAUSR

Abstract A model is proposed to calculate growth restriction factor Qnew for hypoeutectic aluminium alloy by considering not only the liquidus slope, solute concentration and partition coefficient, but also the solute solubility in α-Al and eutectic composition. The relation between α-Al average grain size and Qnew is checked. The results demonstrate that different from the previous growth restriction factor which monotonically depends on the solute concentration c0, Qnew increases first with c0 up to solute solubility in α-Al and then decreases with c0. Grain size increases with the inverse square root of Qnew over the whole range of the hypoeutectic compositions.