Investigation of crack systems in transparent specimens using laser scanning microscope

Using the Laser Scanning Microscope, cracks in transparent materials were i nvestigated. Vickers hardness indentations were made in two types of glasse s and an alpha-Al2O3 single crystal and the crack systems produced examined using image sequences recorded at various different focal positions. The d epth and extent of the lateral cracks produced were measured in the cross s ectional images of the cracks calculated by the computer. Non-reflecting ra dial cracks were also made visible by infiltrating them with a fluorescent liquid.