Variable-Temperature Ion-Exchanged Engineered Stress Profile (Esp) Glasses

A variable-temperature ioin-exchange process was developed to produce strengthened glasses with decreased strength variability. By introducing a high-temperature step into the normal ion-exchange process, the strength variability was greatly decreased with only about 10% loss in the average strength. The surface damage resistance was also studied using indentation strength tests and, again, there was a significant improvement compared with the traditional ion-exchange (isothermal) process.