Abstract
Semisolid casting is the most advanced technology for obtaining granular grains in aluminum-alloy cast structures. The conventional semisolid slurry is produced by electromagnetic or mechanical stirring. Both apparatuses that perform these tasks are large and costly. We developed a simple semisolid casting process for 6070 and 7075 aluminum alJoys using an inclined cooling plate. In this process, numerous granular aluminum crystals are nucleated on the inclined cooling plate while flowing downward. The semisolid slurry was held isothermally in the heat-isolating tundish and the granular grains grew inside. The semisolid slurry was then cast into a horizontal continuous casting machine. The resulting billet was 60 mm in diameter and 600 mm in length. For the 6070 aluminum alloy, the casting speed was 3 mm/s. The finest grain size of 56 μm was obtained by casting at 656°C, and by using the inclined cooling plate of 60° and 200 mm.
