Volume 32, Issue 3 (May 2004)
Residual Stress Measurement in Ion-Exchanged Glass by Iterated Birefringence and Etching
Residual stresses play an important role in controlling fracture behavior in ion-exchanged glass. In this work, the internal tensile stress resulting from ion exchange is measured using conventional birefringence methods. By progressively etching thin layers from the glass surface, the compressive stress in the removed layer can then be determined from the change in the compensating internal tensile stress, producing a stress profile as a function of depth. Specimen geometry, surface roughness, and configuration of the optical system are examined in order to improve the accuracy of the method.