Abstract
Chemically strengthening (ion-exchanged) glass shows high flexural strength due to surface compressive stress. In general, compression is considered to suppress crack generation and reduce brittleness. In order to evaluate cracking behavior for ion-exchanged glass, the crack initiation load and residual stress after vickers indentation for the chemically strengthening soda-lime glass (float glass) was investigated, comparing with the non ion-exchanged glass. The ion-exchange was done in a potassium and sodium nitrate salt bath at potassium concentration of 70-100% at 425 C for 20 h. It has been clarified that chemically strengthening glass was not always less likely to break than non ion-exchanged glass, because it has hard and brittle surface layer and larger residual stress region after indentation.
