Effect of Sn on microstructure and mechanical properties of (Ti-Cu)-based bulk metallic glasses

A Ti 43 Zr 7 Cu 43 Ni 7 bulk metallic glass (BMG) exhibits a plastic strain of less than 0.2% under room-temperature compression. However, a Ti 45 Zr 5 Cu 40 Ni 7.5 Sn 2.5 BMG developed by addition of Sn to Ti 43 Zr 7 Cu 43 Ni 7 shows a significant improvement of 14.8% to the plastic strain with work hardening. Microstructural comparison of these BMGs reveals that the addition of Sn leads to formation of nano-scale chemical heterogeneities throughout the material. These nano-scale chemical fluctuations play an important role in enhancing the plastic strain of (Ti-Cu)-based BMGs.