Drying conditions and their effect on ceramic shell investment casting process

Abstract

The ceramic shell investment casting process has gained an important position in the family of precision casting techniques owing to the scientific advances in many of its aspects, such as binder solutions, refractory materials, pattern materials, and in the manufacturing process. In this endeavour an effort was made to investigate the effect of drying conditions on the performance of ceramic shell moulds. The binder used in this work was an acetone based polysilicic acid, which had been considered as an alternative to the conventionally used binders (namely, ethyl silicate, colloidal silica aquasols etc.). The effects of drying conditions were observed on ceramic wafers, prepared from the slurry, made of fused silica and the binder. The wafers were dried at different temperatures and relative humidity conditions. The effect of drying conditions was observed through the measurement of compressive strength of the ceramic shell wafers. The binder was also subjected to various drying conditions and the characteristic changes of the binder solutions were investigated.