Development of a test technique to determine the thermal diffusivity of large refractory ceramic test specimens

A method has been developed to utilize a high-intensity plasma arc lamp located at Oak Ridge National Laboratory for the measurement of thermal diffusivity of bulk refractory materials at elevated temperatures. The applicability of standardized test methods to determine the thermal diffusivity/conductivity of refractory materials at elevated temperatures is limited to small sample sizes (laser flash) or older test methods (hot wire, guarded hot plate), which have their own inherent problems. A new method, based on the principle of the laser flash method, but capable of evaluating test specimens on the order of 200 mm ×250 mm ×50 mm, has been developed. Tests have been performed to validate the method and preliminary results are presented in this paper.