Advances in Countergravity Lost Foam Casting Process

摘要

A modified countergravity lost foam vacuum process is developed to improve the casting properties and to make possible easy control of the process parameters. The paper presents the results of the foundry experiments focused on the time- and spatial-dependent aspects of mold the filling of two commercial patterns. A small-scale commercial model was designed and fabricated to conduct the experiments to study the thermo- and hydrodynamics of the mold-filling characteristics. A high-sensitivity linear-output capacitive sensor was used to record the rate of sand flow and compaction in a flask while horizontal and/or vertical vibrations were applied. A computer-aided thermometric technique was used to study the heat-related processes in the countergravity lost foam vacuum casting. A complete pattern of vacuum/pressure fluctuations is obtained during countergravity vacuum casting using a bi-directional vacuum/pressure transducer. Tolerance analyses were performed for two Styrofoam~(TM) patterns and their cast products produced by the modified casting procedure.