在定向凝固的条件下,研究了Al-4.5%Cu合金一次晶及二次臂的粗化问题。研究发现,一次枝晶在凝固过程中并不产生粗化,而只与工艺参数有关;二次臂粗化,二次分枝间距与粗化时间t_f的关系是λ_2=0.012—0.020t_f~(0.30-0.38)(mm)。通过与Kattamis等人的粗化理论比较,作者认为Kattamis和Chernov的等温粗化模型同样适用于一般凝固过程。 Under the condition of directional solidification, the coarsening of the primary and secondary arms of Al-4.5% Cu alloy was studied. It is found that primary dendrite does not produce coarsening in the solidification process, but only relates to the process parameters. The secondary arm coarsening, the secondary branch spacing and the coarsening time t_f is related to λ_2 = 0.012-0.020t_f ~ 0.30-0.38) (mm). By comparing with the coarsening theory of Kattamis et al., The authors consider that the isothermal coarsening model of Kattamis and Chernov is equally applicable to the general solidification process.