Specimen size effects on Zr-based bulk metallic glasses investigated by uniaxial compression and spherical nanoindentation
- ORNL
- University of Science and Technology, Beijing
- Steel Structure Research Laboratory, South Korea
Specimen size effects on the mechanical behavior of Zr-based bulk metallic glasses (BMGs) were investigated by compression and nanoindentation tests. In compression, even at the 1- to 10-mm scale, stable shear band propagation and extensive plastic deformation can be achieved in small (2 mm) specimens, in contrast to large (6.5 mm) specimens, which fail catastrophically after limited plastic deformation. The yield strength is independent of specimen size in this range, and plastic deformation remains highly localized in a few shear bands even in those specimens that exhibit stable shear sliding. The fracture surfaces of small specimens are smooth, without the vein patterns normally observed as characteristic features on the fracture surfaces of BMGs. During spherical nanoindentation, it is found that the upper bound of the maximum shear stress to initiate plasticity (yielding) in a Zr-based BMG is almost constant for indenter radii smaller than {approx}90 {micro}m. However, the lower bound of this maximum shear stress decreases with increasing indenter radius, probably due to the increased probability of finding defects underneath larger indenters.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 979599
- Resource Relation:
- Conference: TMS annual meeting 2009, San Francisco, CA, USA, 20090215, 20090215
- Country of Publication:
- United States
- Language:
- English
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