Simulation Study on Wax Injection for Investment Casting

As investment castings grow in size and complexity, control of wax pattern dimensions becomes increasingly important and difficult. Conventionally, mold design and dimensions are re-worked by trial-and-error procedures until casting dimensions are produced within acceptable dimensional tolerances, increasing the cost of the castings.Nowadays, numerical simulation is an efficient tool for mold design. However, one of the critical difficulties in using computer models for the simulation of wax injection process is the lack of material properties of the wax. Material property measurements were conducted in this study that can be used as input in Moldflow. Then, 3D numerical simulation could be applied in analysis with mold design of thin-walled wax pattern, with high dependability. Simulation results of filling time and the location of the air traps were analyzed. Consequently, best gate location and reasonable gate system were determined. The paper highlighted the effectiveness of simulation in filling optimization and deformation of wax pattern.