Journal of the American Ceramic Society, Vol.96, No.9, 2728-2731, 2013
Selective Stress Relaxation on Chemically Strengthened Glass Sheets for Conventional Wheel Cutting
We introduce, for the first time to the best of our knowledge, the use of variable frequency microwave (VFM)-assisted second ion exchange to selectively modify the compressive stress CS in chemically strengthened glass sheets, which allows for separation of these glass sheets into smaller pieces using a conventional cutting tool.The CS in paste-coated zones, in the regions where it is desired for separation of the glass sheets, was successfully manipulated via VFM-assisted second ion exchange, substituting the larger alkali ions in glass by smaller ions of the paste. Its effect on chemically strengthened glass was characterized using a strain viewer, an optical microscope, and an electron probe microanalyzer. We also report on the scribability and breakability across the stress relaxation zones. The results reveal a CS loss of only 3%, from 677 to 656MPa, in the paste-uncoated zones, and complete CS relaxation, down to 0MPa, in the paste-coated regions. The areas of relaxed CS enable the separation of the strengthened glass sheets using conventional wheel cutting.