Thermal And Chemical Strengthening Effects On Crack Initiation In Float Glass

The crack initiation behaviour of chemically and thermally strengthened float glass was studied using a recording microindenter. A Vickers diamond attached to the microindenter was used to produce the indentations. The load and displacement of the indenter were simultaneously recorded on both the loading and unloading cycles of the indentation. Acoustic emissions and optical observation were used to determine the types of cracks formed and the forces at which crack formation occurred during the load-unload cycle. Post-test microscopy was performed to characterise differences in indentation patterns and crack lengths. Dramatic differences in crack initiation were observed between the samples.