High Temperature Refractory Composites and Related Products for use as Thermal, Electrical and Structural Insulation. ZIRCAR Refractory Composites, Inc. produces a comprehensive line of advanced high performance ceramic-ceramic composite materials and related products. Their materials are used around the world in the most demanding thermal, structural and electrical insulating applications ranging in temperatures from 600°C (1112°F) to 1650°C (3002°F). For over thirty years, they have been a problem-solver working with their customers to resolve their thermal management problems. They have developed products that have become industry standards for induction melting, forging and heat treating applications, investment casting, glass processing, hot pressing, as well as many high temperature electrical applications.