Hot Tearing Behavior of ZL205A Alloy Cylindrical Low-Pressure Castings with Slit Gating and Feeding System

In this study, the geometric features of ZL205A alloy castings as well as the formation mechanism of hot tearing under the low-pressure casting process were investigated. To explore the effects of geometric features and the low-pressure casting process on the envelope density and stresses of the ZL205A alloy cylindrical components, pouring experiments were performed, and the solidification process was simulated using the commercial software ProCAST. The results demonstrate that, among the castings with various geometric cross sections, those with round features are most considerably hindered. The experimental results show that hot tearing occurs in the castings when the hindrance factor ε = 0.129 or δ:R = 1:15 at the outside radius of R = 150 mm of the cylindrical components. The simulation results reveal that the position of hot tearing formed in the cylindrical casting is (0.44~0.48)h heights, (0~0.2)δ thickness for a cylindrical envelope with a low-pressure casting process. The combination of copper-rich, hindered stresses and welding stresses causes hot tearing in cylindrical castings.