DEVELOPMENT OF HIGH TEMPERATURE THERMAL CONDUCTIVITY STANDARDS.
Technical rept. 3 Nov 66-3 Nov 68,
LITTLE (ARTHUR D) INC CAMBRIDGE MASS
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The report summarizes the results of an analytical and experimental investigation having as its objective the development of high temperature thermal conductivity and diffusivity standards. Polycrystalline alumina and thoria, arc cast tungsten, RVD graphite and AXM-5Q1 graphite were previously selected as potential candidate standards for experimental evaluation and thermal properties measurement. In the work described in this report, samples of these materials were obtained from commercial sources, examined, characterized, machined and distributed to participating laboratories. Two independent series of measurements of thermal conductivity and thermal diffusivity were made for each sample material over the temperature range from 1000 to 2500C. The data were examined and analyzed for measurement precision, effects of sample variation, comparison with other laboratories data, and comparison with literature data. Of the five materials studied, thoria, tungsten and AXM-5Q1 graphite seem most appropriate for continued evaluation as potential standards. The adequacy of these candidate materials from a chemical and physical stability viewpoint was established over a wide range of anticipated measurement conditions. Specifications for procurement of specimens from commercial sources were also established. Author
- Ceramics, Refractories and Glass