Veränderungen in der Glasoberfläche. Martens-Ritzhärtemeßgerät. Elastisches Verhalten beim Ritzen mit kegelig-polierten Werkzeugen (Achat-, Oxidkeramik- und Diamantkegel). Wellenbewegung in der Oberfläche. Instabile und stabile plastische Deformation.

The film shows the changes occurring in the surface of glass which is deformed by means of scratching tools. The investigation was carried out with a scratching device having a similar mode of action to that of the Martens scratch hardness tester. The elastic behaviour of glass on scratching with conical polished tools is manifested in an undulation of the glass surface behind the tool, which disappears at increasing distance. Agate, oxide ceramic and diamond cones were used as scratching tools. On scratching with the oxide ceramic cone, a slight trace was left on the surface of the glass which indicates a transition to plastic deformation. Scratch tests with a diamond cone at pressure of up to 195 p show the plastic deformation in addition to the elastic deformation of the glass surface.