Semisolid Die Casting of Hypereutectic Al–25%Si Alloy

Abstract

In die casting, it has been shown that the hypereutectic Al–25%Si alloy has excellent fluidity. In this study we clarified that the semisolid Al–25%Si alloy showed better fluidity than did the molten-metal ADC12 alloy, which is a popular Al–Si–Cu alloy for die casting. The result obtained suggests that Al–25%Si alloy is suitable for manufacturing thin die cast products. By using the Al–25%Si alloy, a heat sink model having fins with 50 mm height, thin tops 0.5 mm thick and a draft angle of 0.5°, could be successfully cast at a plunger speed 1.6 m·s⁻¹. It was found that heat dispersion heat dissipation characteristics were not influenced by the reduction in fin thickness. It is concluded that thinner fins manufactured using the semisolid Al–25%Si alloy are useful in reducing the production weight of the heat sink.

 

This Paper was Originally Published in Japanese in J. JSTP 59(693) (2018) 183–188.