Composition design and mechanical properties of ternary Cu–Zr–Ti bulk metallic glasses

• Newly designed monolithic bulk metallic glasses are of good glass-forming ability.
• Cu50Zr44Ti6 exhibits excellent plastic deformation up to ∼7.4%.
• Copious and intersected shear bans are observed in the fractography of Cu50Zr44Ti6.
• Cu50Zr44Ti6 has the best plasticity in the ternary Cu–Zr–Ti bulk metallic glasses.

The new compositions of ternary Cu–Zr–Ti bulk metallic glasses are predicted by integrating calculation of vacancy formation energy, mixing enthalpy and configuration entropy of the alloys based on thermodynamics of glass formers. The monolithic amorphous rods of 3 mm diameter have been successfully fabricated, and characterized by X-ray diffractometry, differential scanning calorimetry, scanning electronic microscopy, transmission electronic microscopy and compression tests. The results show that the designed alloys possess good glass forming ability and excellent mechanical properties. The mechanical properties of the samples can be effectively improved by regulating their composition. The monolithic amorphous rod of Cu50Zr44Ti6 exhibits a high fracture strength of 1855 MPa and excellent plastic deformation up to ∼7.4%. The formation and propagation of shear bands in samples are also investigated. The enhancement of plastic deformation is mainly contributed to multiplication and intersection of shear bands.