Indentation-induced phase transformations in ceramics

This chapter aims to report the detailed analysis of indentation-induced deformation in boron carbide, silicon carbide (SiC), quartz and silica glass and alumina and provides a brief overview of the behaviour of some other ceramics during indentation. Ceramics represent a class of materials that are normally hard and brittle at ambient conditions. Due to their high hardness, ceramics are likely to experience phase transitions during contact loading because the stresses generated near the surface are also high. The fact that indentation leads to relatively high-frequency Raman bands might suggest that a chemical reaction such as oxidation or decomposition to carbon and boron has taken place. Raman microspectroscopy studies indicate that the spectra from hardness impressions in SiC and those from the pristine surface outside the indentation area are significantly different. In the case of SiC there is no correlation between the low-temperature hardness and the phase transformation pressure.