Thermal and mechanical properties of Cu-based Cu-Zr-Ti-Y bulk glassy alloys

A new Cu-based bulk glassy alloy with high tensile fracture strength above 2000 MPa was formed in a (Cu0.6Zr0.3Ti0.1)(98)Y-2 alloy by copper mold casting. The maximum sample thickness for glass formation is 4 mm for Cu60Zr30Ti10 and increases to 5 mm for the 2%Y-containing alloy. The addition of 2%Y also causes an increase in the supercooled liquid region (DeltaT(x) = T-x - T-g) from 36 to 50 K and in the reduced glass transition temperature (T-g/T-l) from 0.62 to 0.63. The increase in the glass-forming ability (GFA) is presumably due to the increase in DeltaT(x) and T-g/T-l. The bulk glassy (Cu0.6Zr0.3Ti0.1)(98)Y-2 alloy exhibits good mechanical properties, i.e., 1780 MPa for yield strength, 2030MPa for tensile fracture strength, 2100 MPa for compressive fracture strength, 1.7% for elastic elongation and 1.5% for plastic elongation. The distinct plastic elongation indicates good ductile nature of the Cu-based bulk glassy alloy. The success of synthesizing the new Cu-based bulk glassy alloy with high GFA and good mechanical properties allows us to expect the extension of application fields as a new engineering material.