| Popis: |
A method has been developed, using cube corner nanoindentation, to measure residual stress in brittle materials. The influence of prevailing stresses on radial crack generation was studied for the residual stress field around a 45N Vickers indent in soda lime glass, using loads of 8-120 mN on the nanoindenter. When aligned in the radial direction of the field, one of the three radial cracks of the cube corner indent increased in length with progression toward the edge of the large Vickers indent. On the other hand, the radial crack of the cube corner indent that was oriented in the tangential direction of the field decreased in length with decreasing distance to the edge of the Vickers indent. Residual stresses were evaluated using the formalism of earlier workers. The stress values obtained were generally higher for the cube corner than for the microVickers method and possible reasons for the difference are discussed. Limitations of the method and sources of error are reported. |
