Structural and thermal investigations of a high-strength Cu-Zr-Ti-Co bulk metallic glass

Cu55Zr30Ti10Co5 bulk metallic glass exhibits a high compressive fracture strength of 2.31 GPa and Young's modulus of 130 GPa, values that are higher than those of other Cu- and Zr-based metallic glasses. The addition of Co to the ternary Cu-Zr-Ti alloy stabilizes the supercooled liquid. On heating, the Cu55Zr30Ti10Co5 metallic glass devitrified and formed an intermediate intermetallic compound prior to reaching equilibrium by diffusion-controlled growth at constant nucleation rate. In the fully annealed state the structure consists of the equilibrium Cu10Zr7 phase with the slightly reduced lattice parameters a = 0.933 nm, b = 0.928 nm and c = 1.254 nm and a small fraction of an unidentified phase.