Strengthening, crack arrest and multiple cracking in brittle materials using residual stresses
US6516634B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 11, 2000 |
| Grant date | Feb 11, 2003 |
| Priority date | — |
| Expiry date | Feb 11, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L5/0047
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.