Research on the solidification characteristic scale and undercooling during directional solidification of single-phase alloy
单相合金定向凝固的特征尺度和过冷度研究

A transparent model alloy,succinonitrile(SCN)-1.48%Salol(mass fraction),was directionally solidified at the constant velocity.The primary dendritic/cellular spacing,tip radius and tip temperature have been measured as a function of growth velocity.The critical velocity for planar interface instability was obtained.It is shown that with the increase of growth velocity,the primary spacing decreases to a local minimum value first,and then increases to a local maximum value,finally decreases again.The cell/dendrite transition happens when the primary spacing increases from the local minimum to maximum value.Experimental results were compared to BH-L and self-consistent models.It is found that the tip temperature predicted by BH-L model shows a large difference with the experimental results,but all experimental results agree with the self-consistent model.