Formation and mechanical strength of bulk glassy alloys in Zr-Al-Co-Cu system

By choosing a new alloy composition of Zr₅₅Al₂₀Co₂₀Cu₅, we succeeded in forming bulk glassy alloys in rod and sheet forms by copper mold casting. The maximum diameter and sheet thickness were 5 mm and 3 mm, respectively. The T_g, ΔT_x and T_g/T₁ are 750 K, 80 K and 0.60, respectively, being independent of sample thickness. The bulk alloy sheet exhibits Young's modulus of 92 GPa, elastic elongation limit of 2.1% and high tensile strength of 1960 MPa. These strength values are considerably higher than those for the other Zr-based bulk glassy alloys reported up to date. The synthesis of the new Zr-based bulk glassy alloy with high glass-forming ability and high tensile strength approaching 2000 MPa is expected to result in a future extension of application fields as a high strength material.