INVESTIGATION OF SINTERABLE OXIDE POWDERS AND CERAMICS MADE FROM THEM
BATTELLE MEMORIAL INST COLUMBUS OH
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A study was made of the strength of nonporous monophase ceramics as a function of their microstructure, and with the basic nature of sinterable powders. Sinterable powders provide a convenient way to study a wide variety of microstructural effects without introducing variations in density or purity. MgO powders, prepared by calcining a high-purity basic MgCO3, were studied as representative examples. The temperature of calcination of the carbonate had a critical effect on the density in sintered compacts of the oxide. The density of compacts of each calcine increased during sintering until a ceiling density was reached after which grain growth occurred without further densification. Ceiling densities of 97 to 98 of theoretical were attained. Sintering in various atmospheres or for extended periods did not affect the attainable density, but sintering in a moisture-free atmosphere reduced the temperature at which the ceiling density was reached. Indications were that sintering atmosphere affected grain growth. The work demonstrated the importance of controlling processing variables to assure uniformly reproducible specimens for strength measurements.
- Ceramics, Refractories and Glass
- Inorganic Chemistry