A Preliminary Study Upon the Applicability of the Direct Water Cooling with the Lost Foam Casting Process

Abstract

Direct water cooling (DWC) application with the lost foam casting (LFC) process was inspired by the ablation casting technique. Ablation casting is designed to combine the controlled filling property of sand mold casting and the rapid cooling of the high-pressure die casting. Briefly, in this method, sand casting is followed by the removal of the mold by water spray and cooling of the part within a short time. The use of special water-soluble inorganic binders facilitates the mold breakdown. However, due to no use of binder materials in the LFC method, the DWC process may become more effective. In this study, similar cooling techniques were applied to the lost foam castings of A356 alloy by two techniques. In the first one, cooling was achieved by tipping the mold content over into a container with a sufficient amount of water after the casting process. The second process was carried out by pouring a sufficient amount of water onto the mold following the casting process. These two developed methods were named as quench casting and splash casting, respectively. It was seen that both methods changed the traditional casting microstructure and properties considerably. A serious decrement in secondary dendritic arm spacing with accompanying modification of the eutectic silicon was observed for the specimens produced via both methods. Hardness values increased significantly, and the results indicate that splash casting is preferable than quench casting because it exhibits better and more stable properties.