Controlling heat radiation for development of high-temperature insulating materials

Conventional industrial insulating materials have a porous structure, and provide good resistance to conduction. However, at high temperatures greater than 1000 degrees C, this structure permits heat transfer through radiation. In recent years, many high-performance insulating materials have been developed that consist of nanosized particles and pores. Such materials have a thermal conductivity less than 0.1 W/(m K) up to 800 degrees C. However, it has very less heat resistance over 1000 degrees C. In this study, we have developed an insulating material which has a great suppress radiation and its thermal conductivity was less than 0.3 W/(m K) at 1500 degrees C. The insulating material was considered to be porous magnesium aluminate spinel of two different pore sizes, 0.05-1 and 1-5 mu m, with a porosity of 78%. Among the two pores, the 1-5 mu m pores were more efficient to restrain heat transfer through radiation. (C) 2014 Elsevier Ltd. All rights reserved.