Abstract
A binary metallic glass (MG) Cu49.3Zr50.7 in the form of thin film was successfully grown on a Si (1 0 0) substrate by magnetron sputtering. The mechanical properties, specifically, hardness and modulus at various peak loads and loading rates were characterized through instrumented nanoindentation. Unlike other metallic glasses showing an indentation size effect (ISE), the composition of this study does not have an ISE, which is phenomenologically the result of the negligible length scale according to the strain gradient plasticity model. The proportional specimen resistance model is applicable to the loaddisplacement behaviors and suggests that the frictional effect is too small to contribute to the ISE. The occurrence of plasticity depends on loading rates and can be delayed so that the displacement during the load holding segment increases logarithmically. In addition, the hardness and modulus are both dependent on the loading rates as well, i.e., they increase as the loading rate increases up to 0.1 mN/s and then hold constant, which is independent of creep time (≤100 s). These loading-rate-dependent behaviors are interpreted as the result of viscoelastic effect rather than free volume kinetics.
Original language | English |
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Pages (from-to) | 340-346 |
Number of pages | 7 |
Journal | Physica B: Condensed Matter |
Volume | 407 |
Issue number | 3 |
Early online date | 4 Nov 2011 |
DOIs | |
Publication status | Published - 1 Feb 2012 |
Keywords
- CuZr
- Indentation size effect
- Loading rate
- Mechanical property
- Metallic glass
- Nanoindentation
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering