Influence of polishing technique on crack resistance of quartz plates

The sensory properties of monocrystalline quartz are influenced by its surface, mechanical properties, and crack resistance. The surface quality of quartz is significantly influenced by its processing technology. The aim of this work is comparative studies of surface morphology, roughness, mechanical properties, and crack resistance of single-crystal quartz plates after chemical–mechanical and magnetorheological polishing. Surface morphology was assessed by atomic force microscopy (AFM). E and H were determined by nanoindentation (NI). The fracture toughness was assessed by the indentation method with visualization of the AFM imprint topography. The task was to determine the most reliable method for calculating the critical stress intensity factor КIC for quartz, adequate to the load range from 0.01 to 0.5 N. It was found that chemical–mechanical polishing creates an altered layer 70 nm thick on the quartz surface, which significantly changes its mechanical properties and КIC.