Thermal Conductivity of Aluminum Borate

Thermal conductivities of sintered aluminum borates were determined in the temperature range from room temperature to 873K by a laser flash method. The thermal conductivities decreased linearly with increasing porosity. By extrapolating these conductivities to zero porosity, the thermal conductivity of a pore-free sintered body was determined. The obtained thermal conductivity had a linear relationship with the reciprocal of absolute temperature. Although the thermal conductivity obtained here is for polycrystalline materials, the value is applicable to single crystals in the same temperature range. The porosity dependence of thermal conductivity is also discussed with several theoretical equations and observed pore structures.