Tuning the glass forming ability and mechanical properties of Ti-based bulk metallic glasses by Ga additions
Publikationen: Beitrag in Fachzeitschrift › Artikel › Forschung › (peer-reviewed)
- Erich Schmid Institute of Materials Science of the Austrian Academy of Sciences
- NIT Durgapur, Department of Metallurgical and Materials Eng. Durgapur
- IFW Dresden
- Technische Universität Darmstadt
- ETH Zürich
A new series of Ti 40 Zr 10 Cu 36−x Pd 14 Ga x (x = 2, 4, 8 and 10)alloys with improved plasticity and glass-forming ability (GFA)are produced. The strategy is to create local structural heterogeneity in Ti-based bulk metallic glasses (BMGs)by alloying with a soft element which has high negative enthalpy of mixing with Ti-atoms. The GFA of Ti 40 Zr 10 Cu 36−x Pd 14 Ga x rods increases with increasing Ga content up to 4 at.%, and for more Ga it decreases. Minor addition of Ga (x = 2)is beneficial to improve the strength and ductility of the TiZrCuPd-based BMG due to the formation of local structural heterogeneities which facilitate the formation of a highly organized pattern of multiple shear bands under quasi-static compression. Ti 40 Zr 10 Cu 34 Pd 14 Ga 2 BMG shows the best combination of compressive global strain and maximum compressive strength of ∼4.5% and ∼2000 MPa, respectively. Comparing the Young's modulus of Ga-containing alloys in amorphous and crystalline state we find that the amorphous state shows significant elastic softening (40–48% smaller)which is useful to reduce stress shielding effect for biomedical applications. The alloys show a remarkable thermoplastic formability as the viscosity decreases sharply by an order of magnitude in the supercooled liquid region.