Effect of high-temperature ambience during sharp indentation on the residual contact site properties
Résumé
Indentation fracture has been used at room temperature to study the residual contact site stemming from sharp contact indentation performed in the 200 - 630 degrees C temperature range followed by cooling to room temperature. The crack system changed from the full set of radial/ median- lateral cracks at room temperature to no cracks beyond 480 degrees C. Microindentation close to the crack- free indents was found to trigger the formation of the full set of crack system. Furthermore, for these indents, lateral cracks were not found except in the presence of radial cracks, a fact that also helps to explain the characteristic geometrical form of the laterals. The shape of the residual stress distribution was found to be very similar for all the temperatures studied, while the spatial extent of the field was found to be temperature dependent.