Abstract
Several thermal properties such as mechanical strength, deformation under load, thermal expansion at high temperatures and refractoriness of foundry mold sand using ultra-rapid hardening cement as a binder were examined.
No remarkable difference in the thermal properties was observed between the mold sand made from special ultra-rapid hardening cement and ordinary portland cement. The higher the mechanical strength of mold sand becomes at room temperature, the smaller becomes the deformation under load at high temperatures (much smaller than that of sand with sodium silicate which is often the cause of mold wall movement). The temperature which induces extraordinary change in thermal properties depends mainly on the chemical composition of silica sand used.
