Glass-ceramic article and method
Abstract
Abstract THIS INVENTION RELATES TO THE STRENGTHENNG OF GLASSCERAMIC ARTICLES WHEREIN THE CRYSTAL CONTENT THEREOF CONSTITUTES THE PREDOMINANT PORTION AND CONTAINING NEPHELINE AS THE PRINCIPAL CRYSTAL PHASE, SAID NEPHELINE CORRESPONDING TO THE FORMULA NA8-XKXAL8SI8O32 WHEREIN X VARIES FROM ABOUT 0.25 TO 4.73. THE STRENGTHENING IS REALIZED THROUGH AN ION EXCHANGE REACTION OCCURRING WITHIN A SURFACE LAYER OF THE GLASS-CERAMIC ARTICLE WHEREIN POTASSIUM, RUBIDIUM, AND/OR CESIUM IONS FROM AN EXTERNAL SOURCE ARE EXCHANGED FOR SODIUM IONS IN THE NEPHELINE TO CONVERT THE NEPHELINE IN PART AT LEAST TO KALSILITE AND/OR CRYSTALS RESEMBLING SYNTHETIC KALIOPHYLITE AND CAUSE COMPRESSIVE STRESSES TO BE DEVELOPED IN THE SURFACE LAYER.
Inventors
- 👤 David A Duke
- 👤 Bruce R Karstetter
Bibliographic Details
Claims Analysis
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