A new ceramic composite based on spherical aluminium oxide for auxiliary panels in high-temperature firing processes

Purpose: The subject of the research and investigation is a new ceramic foundry composite based on a spherical form of aluminium oxide. It is intended to limit the occurrence of technological problems related to the appropriate selection of auxiliary refractory materials, such as cracking, high heat capacity and variable coefficient of thermal expansion. Design/methodology/approach: A composite ceramic material with the spherical form of aluminium oxide included allows to reduce mass and stabilize characteristics of dimensional changes as a function of temperature in auxiliary panels in high-temperature firing processes with typical manufacturing process of the ceramics, which is gravity casting, drying and high-temperature firing. Findings: The study showed that the quantitative share of the spherical form of Al2O3 in the volume of ceramic material has a major impact on its properties. An increased share of spheres translates into greater material porosity and lower matrix density but also, by reducing the cross-section, into decreased strength properties. In the case of the developed ceramic material, there is no visible trend of a decrease in the coefficient of thermal expansion with increasing temperature, which is the case with traditional ceramic materials. Research limitations/implications: The strength of presented composite isn’t good and constitutes a further direction of research and development of the material. Practical implications: Although decreased strength properties, the composite with no visible trend of a decrease in the coefficient of thermal expansion with increasing temperature could be used as panels in high-temperature firing processes. Originality/value: New ceramic foundry composite based on a spherical form of aluminium oxide for auxiliary panels in high temperature processes.