Effect of Sn and Al additions on the microstructure and mechanical properties of amorphous Ti-Cu-Zr-Ni alloys

Amorphous Ti-Cu-Zr-Ni alloys with minor addition of Sn and Al were prepared by melt spinning technique. The effects of Sn and Al additions on the microstructures and mechanical properties of glassy ribbons were investigated. The amorphous state of ribbons was confirmed by x-ray diffraction and transmission electron microscopy, where those ribbons with Sn addition exhibited a fully amorphous state. The characteristic temperature indicates that Ti45Cu35Zr10Ni5Sn5 alloy has a stronger glass-forming ability, as proven by differential scanning calorimetry. Ti45Cu35Zr10Ni5Al5 alloy showed a better hardness of 9.23 GPa and elastic modulus of 127.15 GPa and good wear resistance. Ti45Cu35Zr10Ni5Sn5 alloy displayed a pop-in event related to discrete plasticity according to nanoindentation. When the temperature is below 560 K, Ti45Cu35Zr10Ni5Sn5 alloy mainly exhibits elasticity. When the temperature rises between 717 K and 743 K, it shows a significant increase in elasticity but decrease in viscoelasticity after the ribbon experiences the main relaxation at 717 K. When the temperature is above 743 K, the ribbon shows viscoplasticity.