Viscous Flow And Surface Crystallization Caused By Vickers Indentation

Healing and nucleation activity of crack patterns caused by Vickers micro-indentations on the surface of diopside glass (MgO.CaO.2SiO2) were studied by optical and surface interference microscopy. Minimising the glass surface during thermal treatments and healing of cracks result in funnel-like depressions symmetrically arranged around the Vickers indentation. Diopside surface crystals predominantly grow from previous crack edges. Thus, double chains of crystals reveal completely healed radial cracks while long range viscous flow at the formation of funnel-like depressions spreads off former double chains to form circular crystal chains.