Thermal diffusivity of the candidate standard reference material cordierite VERTRAULICH

The results of an international programme carried out to qualify transfer or reference standards for thermal transport properties, thermal conductivity and thermal diffusivity, in the range between 1 Wm-1 K-1 and 5 Wm-1 K-1, are reported. It was necessary to cover the gap in the availability of reference standards among ceramic high-temperature materials appropriate for use above 800°C. A well-suited candidate material has been found in commercial cordierite manufactured by Ceramtec AG, large batches of which are regularly produced for various articles and components under a standard procedure. The programme carried out under the auspices of the German task group "Thermophysik" involved thermal diffusivity measurements at the Institute for Nuclear Technology and Energy System (IKE) of the University Stuttgart, Germany, the Institute of Nuclear Science Vinca (Vinca), Yugoslavia, the Austrian Research Center Seibersdorf (FZS), Austria, and the Brandenburg Technical University (BTU) at Cottbus, Germany. Measurements of thermal diffusivity carried out by different experimental techniques and by varying various relevant parameters gave results which are in very good agreement. Experimental results are presented and discussed.