Casting Ring Liners XVII : Thermogravimetry of Casting Ring Liners

Abstract

Thermogravimetric analysis of 46 casting ring liners in 9 groups was performed to investigate the effect of the organic binder component in the ring liners on the thermal expansion of gypsum-bonded cristobalite investments. As the results, the weight of the ring liner started decreasing from around 250℃ on the rise in temperature until around 550℃. The peak temperature of the largest peak in the differential of the thermogravimetric (DTG) curve was over 290℃ for all ring liners. In the casting ring lined with a ring liner, the temperature range showing the rapid expansion of gypsum-bonded cristobalite investments was possibly shifted to the high temperature side.