Sintering of Ceramic Particulate Composites: Effect of Matrix Density |
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Authors: | Mohamed N Rahaman Lutgard C De Jonghe |
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Affiliation: | Ceramic Engineering Department, University of Missouri, Rolla, Missouri 65401;Lawrence Berkeley Laboratory, Materials Sciences Division, and Department of Materials Science and Mineral Engineering, University of California, Berkeley, California 65401 |
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Abstract: | Composites consisting of a fine-grained, polycrystalline zinc oxide matrix and <10 vol% coarse, rigid silicon carbide inclusions were prepared by the same mixing procedure and then compacted to produce samples with matrix densities of 0.45 and 0.68 of the theoretical. The samples were sintered under identical temperature profiles in separate experiments that employed either a constant rate of heating of 4°C/min or near isothermal heating at 735°C. The ratio of the densification rate of the composite matrix to the densification rate of the unreinforced zinc oxide was found to be independent of the initial matrix density. This ratio increased significantly with temperature in the constant-heating-rate experiments but was relatively constant in the isothermal experiments. The results indicate that microstructural coarsening may be an important mechanism for explaining the reduced sinterability of polycrystalline matrix composites. |
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Keywords: | sintering zinc oxide silicon carbide density inclusions |
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