Abstract 1. A PROCESS OF MAKING AN ARTICLE HAVING A MAIN BODY PORTION OF GLASS-CERAMIC AND AN INTEGRAL SURFACE LAYER OF GLASS-CERAMIC AND HAVING A LOWER COEFFICIENT OF LINEAR EXPANSION THAN THAT OF THE MAIN BODY PORTION WHICH COMPRISES: (1) FORMING AN ARTICLE FROM A THERMALLY CRYSTALLIZABLE GLASS CONTAINING LITHIA, ALUMINA AND SILICA IN AN OVERALL COMPOSITIONS, INCLUDING NUCLEANT, BEING CAPABLE OF UNDERGOING BULK CYRSTALLIZATION TO FORM UPON BULK CRYSTALLIZE THE GLASS TO A GLASS-CERAMIC WHEREIN BB-SPODUMENE AS THE PREDOMINANT CRYSTALLINE PHASE, AND (2) HEAT TREATING THE GLASS ARTICLE TO THERMALLY IN SITU CRYSTALLIZZE THE GLASS TO A GLASS-CERAMIC PHASE, SPODUMENE IS THE PREDOMINANT CRYSTALLINE PHASE, (3) HEATING THE SURFACE LAYER OF THE GLASS-CERAMIC TO AN ELEVATED TEMPERATURE OF THE SURFACE OF THE ARTICLE THE GLASS-CERAMIC OF THE SURFACE LAYER OF THE ARTICLE BACK TO THERMALLY CRYSTALLIZABLE GLASS WHILE MAINTAINING THE MAINBODY OF THE ARTICLE AS GLASS-CERAMIC, AND (4) HEAT TREATING THE ARTICLE TO CONVERT THE GLASS OF THE SURFACE LAYER TO GLASS-CERAMIC CONTAINING B-EUCRYPTITE AS THE PREDOMIANT CRYSTALLINE PHASE AND WHICH HAVE A LOWER EXPANSION COEFFICIENT RELATIVE TO THE GLASSCERAMIC OF THE MAIN BODY PORTION, WHEREBY THE ARTICLE FORMED HAS A FLEXUAL STRENGTH GREATER THAN THE INITIAL ARTICLE OF GLASS-CERAMIC.
A PROCESS OF MAKING AN ARTICLE HAVING A MAIN BODY PORTION OF GLASS-CERAMIC AND AN INTEGRAL SURFACE LAYER OF GLASS-CERAMIC AND HAVING A LOWER COEFFICIENT OF LINEAR EXPANSION THAN THAT OF THE MAIN BODY PORTION WHICH COMPRISES: (1) FORMING AN ARTICLE FROM A THERMALLY CRYSTALLIZABLE GLASS CONTAINING LITHIA, ALUMINA AND SILICA IN AN OVERALL COMPOSITIONS, INCLUDING NUCLEANT, BEING CAPABLE OF UNDERGOING BULK CYRSTALLIZATION TO FORM UPON BULK CRYSTALLIZE THE GLASS TO A GLASS-CERAMIC WHEREIN BB-SPODUMENE AS THE PREDOMINANT CRYSTALLINE PHASE, AND (2) HEAT TREATING THE GLASS ARTICLE TO THERMALLY IN SITU CRYSTALLIZZE THE GLASS TO A GLASS-CERAMIC PHASE, SPODUMENE IS THE PREDOMINANT CRYSTALLINE PHASE, (3) HEATING THE SURFACE LAYER OF THE GLASS-CERAMIC TO AN ELEVATED TEMPERATURE OF THE SURFACE OF THE ARTICLE THE GLASS-CERAMIC OF THE SURFACE LAYER OF THE ARTICLE BACK TO THERMALLY CRYSTALLIZABLE GLASS WHILE MAINTAINING THE MAINBODY OF THE ARTICLE AS GLASS-CERAMIC, AND (4) HEAT TREATING THE ARTICLE TO CONVERT THE GLASS OF THE SURFACE LAYER TO GLASS-CERAMIC CONTAINING B-EUCRYPTITE AS THE PREDOMIANT CRYSTALLINE PHASE AND WHICH HAVE A LOWER EXPANSION COEFFICIENT RELATIVE TO THE GLASSCERAMIC OF THE MAIN BODY PORTION, WHEREBY THE ARTICLE FORMED HAS A FLEXUAL STRENGTH GREATER THAN THE INITIAL ARTICLE OF GLASS-CERAMIC.
Claim 2
Dependent Claim
199 words
A PROCESS OF MAKING AN ARTICLE HAVING A MAIN BODY PORTION OF GLASS-CERAMIC AND AN INTEGRAL SURFACE LAYER OF GLASS-CERAMIC AND HAVING A LOWER COEFFICIENT OF LINEAR EXPANSION THAN THAT OF THE MAIN BODY PORTION WHICH COMPRISES: (1) FORMING AN ARTICLE FROM A THERMALLY CRYSTALLIZABLE GLASS CONTAINING LITHIA, ALUMINA AND SILICA IN AN OVERALL COMPOSITIONS, INCLUDING NUCLEANT, BEING CAPABLE OF UNDERGOING BULK CYRSTALLIZATION TO FORM UPON BULK CRYSTALLIZE THE GLASS TO A GLASS-CERAMIC WHEREIN BB-SPODUMENE AS THE PREDOMINANT CRYSTALLINE PHASE, AND (2) HEAT TREATING THE GLASS ARTICLE TO THERMALLY IN SITU CRYSTALLIZZE THE GLASS TO A GLASS-CERAMIC PHASE, SPODUMENE IS THE PREDOMINANT CRYSTALLINE PHASE, (3) HEATING THE SURFACE LAYER OF THE GLASS-CERAMIC TO AN ELEVATED TEMPERATURE OF THE SURFACE OF THE ARTICLE THE GLASS-CERAMIC OF THE SURFACE LAYER OF THE ARTICLE BACK TO THERMALLY CRYSTALLIZABLE GLASS WHILE MAINTAINING THE MAINBODY OF THE ARTICLE AS GLASS-CERAMIC, AND (4) HEAT TREATING THE ARTICLE TO CONVERT THE GLASS OF THE SURFACE LAYER TO GLASS-CERAMIC CONTAINING B-EUCRYPTITE AS THE PREDOMIANT CRYSTALLINE PHASE AND WHICH HAVE A LOWER EXPANSION COEFFICIENT RELATIVE TO THE GLASSCERAMIC OF THE MAIN BODY PORTION, WHEREBY THE ARTICLE FORMED HAS A FLEXUAL STRENGTH GREATER THAN THE INITIAL ARTICLE OF GLASS-CERAMIC.