Real-time Embedded Sensing for Process Monitoring and Quality Control in the Lost Foam Casting Process

The Lost Foam Casting (LFC) process employs a sacrificial foam replica of the desired casting that is supported by an unbonded sand mold through an overhead raining and flask vibration stage. Generally, the raining and vibration is programmed to a pattern-specific schedule to adequately promote fluidized sand flow into pattern cavities and produce proper densification. Currently, a lengthy trial-and-error process is often employed for determining an acceptable raining and vibration schedule for specific molds. Generally, this stage relies heavily on simple measurements and operator experience for adjustment and tuning of the mold production control and timing. This paper presents results from deployment of several embeddable sensors on a horizontal compaction table to measure mold parameters for process monitoring and quality control. Accelerometers were utilized to measure characteristic vibration changes across the flask during sand filling and densification. Additionally, foam patterns and flask walls were instrumented with low-cost thin-film force sensors to gauge the development of sand pressure during the cycle.