Thermal treatment of ion-exchanged glass

Abstract

Thermal treatments of ion-exchanged glasses are often needed for postprocessing steps, including deposition or curing of inorganic or organic coatings deposited on the glass surface. In this study, we investigate the effects of post–ion exchange thermal treatment on the concentration profile, residual stress, and final strength of the ion-exchanged glass. A new general solution of the diffusion problem with variable boundary conditions is presented together with its integration in a recent residual stress model, including fast and slow relaxation terms. Strength is evaluated as a function of the surface flaw depth in both solely ion-exchanged glass and ion-exchanged glass subjected to subsequent thermal treatments. Results indicate that the thermal treatment may have significant detrimental consequences in terms of strength, which should be carefully considered in the design of glass components to avoid unexpected immediate or time-delayed breakages.