Deformation features of mono-, polycrystalline and amorphous quartz during depth-sensing indentation

Abstract

The phenomenon of plastic instability (steps) arising during depth sensing indentation (DSI) measurements of different types of quartz: α-SiO2, p-SiO2 and a-SiO2 is investigated. It is shown that plastic deformation of all types of quartz is characterized by two main mechanisms: shear flow and compaction of the structure. It is suggested that quartz deformation during DSI occurs by a special twinning mechanism, an atomic-rotational type mechanism, with a nanoscopic change in shape, in contrast to conventional (translational-rotational) twinning.