Dimensional accuracy of investment shells made from refractory ceramic media is a critical requirement during the casting and solidification process. Expansion and plastic deformation of the shell wall is a cause of dimensional defects in investment casting. Monitoring and circumventing the root cause of investment shell deformation can enhance quality of cast products. This study looked at the thermo-mechanical behavior of a disc shaped investment shell specimen, by means of a thermal distortion measurement system that has been developed at Western Michigan University. Using this system, vertical and radial deformation of the investment casting shell materials was measured and analyzed.

The method is simple and easy to use for rapid analysis of investment shell materials. Measurement data from an investment shell materials were collected and analyzed. The results are thermal distortion curves that reveal dynamic behavior of the specimen that is critical in achieving sound dimensional characteristics in investment castings. The system can be used to establish a materials control program and for dimensional control of investment shell materials. It would aid in identifying correct amounts of investment matrix and stucco, and for predicting the behavior of the investment casting shell material in thermo-mechanical application.