Characterization of Synthesized Tetragonal Zircon and Study of its Application as a High-Temperature Insulating Material

Objective: This paper has focused on the preparation of a high-temperature composite material from naturally available beach sand zircon minerals. Methods: Initially, zirconia was prepared from natural zircon minerals through a chemical route. Further, synthetic zircon was prepared by the calcination of zirconia and silica. The product was characterized by examining the water absorption capacity, apparent porosity, dielectric strength, XRD, chemical analysis, TEM, electrical resistance, relative density, and thermal stability properties. The insulation properties were studied by applying synthetic zircon coatings on base materials. The analysis of the results was carried out by using an artificial neural network (ANN). Results: The dielectric strength was found to be 10.2 kV/mm at a temperature of 1500oC. XRD analysis confirmed the occurrence of tetragonal zircon (t-zircon), which is thermally stable up to 1500oC. Conclusion: TEM results confirmed the synthetic zircon to lie in the nano-size range. XRD analysis confirmed that the synthesized zircon retained ~100% of the tetragonal zircon phase even after calcination at 1500°C, indicating excellent thermal stability at that temperature. The electrical resistance of synthetic zircon was found to be in the range of 200-210MΩ. The comparative study confirmed synthetic zircon to have the potential to be used for high-temperature structural and functional applications, including its preliminary use in thermal barrier systems.