Ductile Bulk Metallic Glass
Abstract
We report on experimental evidence of pronounced global plasticity measured in monolithic Pt57.5Cu14.7Ni5.3P22.5 bulk metallic glass under both bending and unconfined compression loading conditions. A plastic strain of 20% is measured, never before seen in metallic glasses. Also, permanent deformation and a strain exceeding 3% before failure is observed during bending of 4mm thick samples. To date, no monolithic metallic material has exhibited such a combination of high strength, extensive ductility, and high elastic limit. The large plasticity is reflected in a high Poisson ratio of 0.42, which causes the tip of a shear band to extend rather than initiate a crack. This results in the formation of multiple shear bands and is the origin of the observed large global ductility and very high fracture toughness, approximately 80 MPa m-1/2.
- Publication:
-
Physical Review Letters
- Pub Date:
- December 2004
- DOI:
- 10.1103/PhysRevLett.93.255506
- Bibcode:
- 2004PhRvL..93y5506S
- Keywords:
-
- 81.05.Kf;
- 62.20.Fe;
- 81.05.Zx;
- 83.60.Rs;
- Glasses;
- Deformation and plasticity;
- New materials: theory design and fabrication;
- Shear rate-dependent structure