Aluminum Processing: Casting
Casting generally uses vertical or horizontal water-cooled semi-continuous casting. In order to improve the microstructure and surface quality of the vertical casting, the electromagnetic crystallization tank, the short crystallization tank and the hot top casting method have also been developed. The water-cooled semi-continuous casting method introduces liquid metal into a water-cooled crystallizer through a launder, and cools the liquid metal to form a solidified outer shell, which is pulled by the casting machine base or uniformly lowered by its own weight to be separated from the crystallizer to form a billet. The process parameters vary greatly depending on the alloy composition and the size of the billet. Generally, the casting speed and cooling rate should be increased as much as possible to reduce the height of the crystallization tank. The casting temperature is usually 50 to 110 ° C higher than the liquidus of the alloy. In addition, a continuous casting and rolling process for aluminum strips has been developed.