Microstructures of some typical refiners

including Al-Ti-B

Al-Ti-C

Al-Ti and Al-B master alloy

were observed and their refinement effects on A356 alloy were examined. The results show that secondary phase size and distribution in A356 alloy can affect refinement effect with Al-Ti-B master alloy. 4# refiner from the Holand with small Al

3

Ti size and uniformly distributed TiB

2

have the most refining effects on the A356 alloy among these refiners

in which the size of primary Si phase is 500 μm at holding for 30 min with 0.2% addition. As 0.2% and 0.5% additions for these four kinds of refiners

Al-Ti-B has the most refinement effects on the A356 alloy. The refinement effects had no obvious difference at a high cooling rate while Al-3B refiner is better at lower cooling speed for the four kinds of refiners.