Study on the Thermal Expansion Performance of Gypsum in the Application of Precision Casting

Gypsum is a very important cementitious material in gypsum-based precision casting. The thermal expansion characteristics of gypsum have great influence on the adjustment of gypsum type precision casting powder formula. In this paper, the thermal expansion properties of different gypsums such as β-gypsum, natural gypsum-based α-gypsum, desulfurization gypsum-based α-gypsum, and the influence of temperature, heating rate/heating mode on the thermal expansion properties of α-gypsum are studied, which can provide references for the application of gypsum in the precision casting.