Strengthening, crack arrest and multiple cracking in brittle materials using residual stresses

Patent · Tue Feb 11 04:00:00 EST 2003

OSTI ID:879644

Green, David J.; Sglavo, Vincenzo M.; Tandon, Rajan

Embodiments include a method for forming a glass which displays visible cracking prior to failure when subjected to predetermined stress level that is greater than a predetermined minimum stress level and less than a failure stress level. The method includes determining a critical flaw size in the glass and introducing a residual stress profile to the glass so that a plurality of visible cracks are formed prior to failure when the glass is subjected to a stress that is greater than the minimum stress level and lower than the critical stress. One method for forming the residual stress profile includes performing a first ion exchange so that a first plurality of ions of a first element in the glass are exchanged with a second plurality of ions of a second element that have a larger volume than the first ions. A second ion exchange is also performed so that a plurality of the second ions in the glass are exchanged back to ions of the first element.

• Research Organization: Pennsylvania State University, University Park, PA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: FG02-86ER45252
• Assignee: The Penn State Research Foundation (University Park, PA)
• Patent Number(s): 6,516,634
• Application Number: 09/502,284
• OSTI ID: 879644
• Country of Publication: United States
• Language: English