Glass-ceramics and color methods
AssigneeCorning Incorporated
InventorRobert W. Pfitzenmaier
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Abstract
A method of varying the color in a glass-ceramic material having a beta-quartz solid solution as the predominant crystal phase which comprises controlling the Al.sub.2 O.sub.3 level between 19 and 20% by weight, the Fe.sub.2 O.sub.3 level between 700 and 900 ppm and the Co.sub.3 O.sub.4 level between not over 15 ppm and 140 ppm. An amber color is obtained with 20-40 ppm Co.sub.3 O.sub.4 and a burgundy color with 120-140 ppm Co.sub.3 O.sub.4. Co.sub.3 O.sub.4 in a compatible carrier may be added to molten glass as a forehearth additive.
Claims15
A method of producing a glass-ceramic that is capable of having a variety of colors induced therein which comprises formulating and mixing a batch for a base glass that is capable of being thermally crystallized to a glass-ceramic having a beta-quartz solid solution as a predominant crystal phase, including TiO.sub.2 in the batch in an amount effective as a nucleating agent and sufficient to provide up to about 6% in the glass including Al.sub.2 O.sub.3, Fe.sub.2 O.sub.3, and Co.sub.3 O.sub.4 in the glass batch in amounts sufficient to provide 19-20% Al.sub.2 O.sub.3, 700-900 ppm Fe.sub.2 O.sub.3, and not over 15 pp. Co.sub.3 O.sub.4 in the glass, melting the batch in a melting unit, and delivering the molten glass through a forehearth.
A method of producing a variety of colored glass-ceramic products which comprises melting a base glass that is capable of being thermally crystallized to a glass-ceramic having a beta-quartz solid solution as a predominant crystal phase, the base glass composition including 19-20% Al.sub.2 O.sub.3, 700-900 ppm Fe.sub.2 O.sub.3, and TiO.sub.2, the TiO.sub.2 being in an amount effective as a nucleating agent, but not over 6%, incorporating Co.sub.3 O.sub.4 in the base glass, and thermally crystallizing the glass to a glass-ceramic having a beta-quartz solid solution as a primary crystal phase, the amount of Co.sub.3 O.sub.4 incorporated in the glass determining the color of the glass-ceramic.
A colored, transparent glass-ceramic having a beta-quartz solid solution as its primary crystal phase, containing an amount of TiO.sub.2 effective as a nucleating agent up to about 6%, and having a color package composed of 20-140 ppm Co.sub.3 O.sub.4, 700-900 ppm Fe.sub.2 O.sub.3 and 19-20% Al.sub.2 O.sub.3.
Dependencies are inferred from the claim text.