Effect of Stucco Size, Shell Thickness, and Pre-Heating Temperature on Shell Permeability in Investment Casting

The permeability is an important mold characteristic affecting the quality of investment casting components. In this research, the effect of stucco grain size and mold thickness on the permeability of mold was studied. The alumino–silicate stuccos with 50/80, 30/50, and 16/30 mesh sizes were used to prepare molds. The molds were developed with 6mm, 8mm, and 10mm thicknesses. The ping-pong ball method was used to measure the permeability of molds. The permeability of molds was also measured at elevated temperatures to analyze the effect of temperature. The permeability was observed greater in molds with finer stuccos as compared to coarse stucco. It has been also observed that with the increase in temperature, the permeability of the mold decreases. Along with permeability finer stucco has also exhibited promising mold strength.