Metallurgical Structure of Hypoeutectic Al-Si Alloy Solidified Under Water Cooling Conditions

The ablation casting process was invented as a new casting process by solidifying the casting
under water cooling to improve foundry products quality. The purpose of this research was to study the
metallurgical structure of hypoeutectic Al-Si alloy (A356) solidified under water cooling conditions.
The solidification times before water cooling were selected as 50, 100, 150, and 200 s after pouring
melts. The experimental results revealed that the secondary dendrite arm spacing (SDAS) could
decrease from the normal solidified 62 μm to 29 μm in the water cooling condition. The microstructural
evidences revealed that solidified under water cooling results in more fine and homogeneous structure
compared to the normal solidified. In addition, the hardness of as-cast and T6 treated samples are
significantly enhanced. It could be concluded that casting under water cooling is an effective method
for improving quality in aluminum foundry.