The mechanical behaviour of Ti-based bulk metallic glass during consecutive load-unload nanoindentation cycles, using progressively larger forces, is investigated. Indentation cycles allow evaluating the contact stiffness and, therefore, the hardness and Young's modulus as a function of the penetration depth. The indentation hardness shows a gradual decrease as the applied load increases, evidencing the occurrence of an indentation size effect. An increase of contact stiffness is also observed during the indentation cycling process, an effect which is accompanied with a slight reduction of the Young's modulus. These observations are consistent with the presumption that metallic glasses become structurally modified during the course of nanoindentation experiments. In particular, a deformation-induced increase in the amount of free volume occurs within the amorphous structure, leading to a concomitant mechanical softening. © 2010 American Scientific Publishers.
|Journal||Nanoscience and Nanotechnology Letters|
|Publication status||Published - 1 Dec 2010|
- Indentation size effect
- Mechanical properties
- Metallic glass