Abstract
In the glass manufacturing process, it is very important to understand the crack initiation behavior of glass. But only a few paper have been published on the scratch-induced cracking in glass. In this study, the crack initiation behavior at the groove-edge was examined through the low-speed knoop scratch test for several silicate glasses. The crack initiation loads of silica and lead silicate glasses are lower than those of soda-lime and Tempax glasses. The lower initiation load in lead silicate should be attributed to its low fracture toughness. On the other hand, silica glass has high fracture toughness and low crack initiation load. It is known that silica glass is easily densified by indentation accompany with the formation of large residual stress. This should be the reason for the low crack initiation load in silica glass.
