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High‐Fire Opaque Glazes for Zircon Bodies
Author(s) -
GORDON D. V.
Publication year - 1951
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1951.tb13026.x
Subject(s) - materials science , gloss (optics) , zircon , mineralogy , crazing , barium , magnesium , opacity , oxide , metallurgy , texture (cosmology) , composite material , geology , geochemistry , coating , optics , polymer , physics , image (mathematics) , artificial intelligence , computer science
This investigation covers two systematic studies of raw, one‐fire, zirconium‐opacified glazes applied to two bodies of approximately 60% zircon content and fired to cones 11, 12, and 14. (1) Variations in alumina and silica were investigated in order to determine the best content and ratio of these refractory oxides. It was found that compositions having 0.6 molecular equivalents of alumina, with silica‐alumina ratios ranging from 9 to 11, gave the best results in gloss and texture at cones 11, 12, or 14. The best resistance to crazing was obtained when the glazes were fired to cone 14. (2) A triaxial series of glazes was investigated in which three fluxes, magnesium, calcium, and barium oxides, were varied. Glazes containing 0.55 to 0.65 equivalent of magnesium oxide had good gloss and texture and the best resistance to crazing over the entire range of firing. Glazes containing similar amounts of barium oxide had higher luster, but inferior texture, and were less resistant to crazing except when fired at cone 14. Glazes having calcium oxide contents in excess of 0.25 molecular equivalent crazed when fired at cones 11 and 12. Throughout the range of firing the glazes high in magnesium oxide maintained the best texture; the barium oxide glazes had the best gloss. The suitability of the better glazes developed in the investigation for bodies of very high zircon content was established by supplementary tests on four additional bodies containing from 72 to 90% zircon.