The differential thermal analysis technique aided by microcomputer is used to record and analyze cooling curves and differential curves of ZL104 alloy melt with sodium modification agents and the relation ship between the effect of modifiction and Δ T

S

t e of the curves has been established. According to Δ T (eutectic growth temperature difference between unmodified and modified melt) and S (peak value of the end of the eutectic growth plateau in differential curve) and t e (time of the eutectic growth)

the effect of modification of ZL104 alloy can be predicated rapidly and reliably.