Die-casting of product with thin fins by Al-25%Si

Abstract

Casting of aluminium alloys, which have excellent fluidity but solidification difficulty, was investigated using a vertical type high-speed twin-roll caster. The results showed that Al-25% exemplifies these characteristics. The fluidity of the Al-25%Si was better than that of A383, which is a popular aluminium alloy for die casting. It is estimated that its large latent heat contributes to the good fluidity. Die casting of a model heat sink with thin fins was achieved using Al-25%Si. The thickness of the fin top was 0.5 mm, the draft angle was 0.5° and the height was 50 mm. The heat sink model cast from Al-25%Si had smaller thermal resistance and lighter weight compared with the conventional type heat sink model cast from A383.