Abstract
This paper describes the feasibility of the ductile mode scratching of optical glasses by a sharply pointed tip diamond indenter Scratching experiments were carried out with computer controlled nanoindentation-hardness apparatus equipped with trial manufactured parallel plate type force sensor, PZT actuators and mounted in a vacuum chamber of scanning electron microscope. It was found that at low normal loads P<0.1mN cracks P>0.1mN lateral cracks were well observed. The fracture mechanism of the scratching test is well described in this study by the microplasticity zone of the hypothetically stress-strain diagram for brittle materials. The coefficient of proportionality between the mean pressure on a diamond tip during scratching and the static pressure during indentation has been determined experimentally.
