Under sharp contact loading, glass deforms elastically and then plastically in the form of densification, shear flow, and network structure changes, which interplay with each other and lead to stress/residual stress buildup and cracking. Vickers indentation is often used to study the deformation and cracking behavior of glass; however, it is not easy to delineate the individual contribution of each deformation mode under indentation due to experimental difficulties associated with in situ investigations at a local scale (tens of microns) under nonuniform stresses. Given the stress field under an indenter is largely compressive, hydrostatic compression and decompression in a diamond anvil cell (DAC) were used in this work to help understand the response of glass to indentation during the loading and unloading process. To this end, an optical microscopy technique was developed to measure the volume of glass under pressure in the DAC by using argon as a pressure transmitting medium. This provided the densification and recovery of glass under hydrostatic compression and decompression. In situ Brillouin light scattering experiments were carried out at the same time to measure the elastic response of glass to pressure. A few multicomponent glasses with vastly different indentation cracking behaviors were selected for study in this work. Our experiments reveal that glass with a high ability to undergo reversible structure changes in response to hydrostatic compression and decompression shows a high cracking resistance under sharp contact loading.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Physics and Astronomy (miscellaneous)