Development of a technology for the production of ceramic moulds with reduced thermal conductivity to control the solidification of thin-walled castings

During the project a technology of making ceramic moulds using aluminosilicate microspheres was developed. According to the developed technology, ceramic samples were used to determine thermal conductivity in the temperature range of 500°C to 850°C. In this temperature range, thermal conductivity is about 0.5 W/mK. Strength measurements were conducted using a four-point bending technique. The strength of the developed ceramics and typical ceramics made from molochite materials is similar. Computer simulations facilitated the design of experimental moulds. The recording of Al alloy cooling curves in rectangular insulated and non-insulated moulds allowed for comparison of the thermal parameters of both types of moulds (i.e. ceramics). There was also a castability test performed using the moulds with a “grille” model with 1.5 × 1.5 mm channels, which determined the effect of increased material insulation on the number of properly filled mesh of the mould.