Dissolution in Ceramic Systems: III, Boundary Layer Concentration Gradients |
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| Authors: | Y OISHI A R COOPER JR W D KINGERY |
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| Affiliation: | Ceramics Division, Department of Metallurgy, Massachusetts Institute of Technology, Cambridge, Massachusetts |
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| Abstract: | By use of electron microbeam probe analysis on quenched samples, the concentration distribution of CaO, A12O3, and SiO2 was determined across the boundary layer between molten calcium aluminum silicates and dissolving or growing sapphire and fused silica. A definite shift in the concentration ratios of the solvent components was found near the interface. Analysis of diffusion flux equations for a ternary system successfully related the shift in concentration ratio to the intrinsic diffusion coefficient for each component. For alumina dissolution in a melt rich in CaO, evidence of incongruent dissolution was observed with the formation of new phases, CaO· 6Al2O3 and CaO· 2A12O3. |
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