Effect of JDN-I flux on DAS of A356 alloy at different cooling rate

A novel JDN-I flux containing a rare earth compound that has been studied has great effect on the secondary dendrite arm spacing (DAS) of A356 alloy. The experimental results indicate that the DAS (λ2) obtained by water-quenching decreases by 30.8% in comparison with that by air-cooling without the covering of the flux, while λ2 obtained by water-quenching decreases by 88.2% in comparison with that by air cooling with the covering of JDN-I flux. It is shown that there are two critical cooling rates, T1 and T2. If the cooling rate TT2, λ2 is determined by the [RE] of JDN-I flux and solidification time tf. If T1<T<T2, λ2 is determined by tf, [RE] and M together