Formation and mechanical properties of Cu-Zr-Ti bulk glassy alloys

Cu-base bulk glassy alloys with high glass-forming ability were fabricated in Cu-Zr-Ti ternary system by copper mold casting. The critical diameter for glass formation was 5 mm for Cu₆₀Zr_40-xTi_x (x=7.5%, 10%, 12.5%) alloys, 4 mm for Cu₆₀Zr₂₅Ti₁₅ alloy and 3 mm for Cu₆₀Zr_40-xTi_x (x=15%, 17.5%, 22.5%, 25%) alloys. The glassy alloys exhibited distinct glass transition together with supercooled liquid region at 38-65 K. The Young's modulus, compressive fracture strength, plastic strain and Vickers hardness (Hv) of the bulk glassy alloys are in the range of 80-114 GPa, 1730-1865 MPa, 0.3%-1.5% and Hv 693-Hv 824 respectively, and increase with the increase of Ti content in the alloys. The discovery of the Cu-based bulk glassy alloys with high glass-forming ability, high fracture strength and distinct plastic strain indicates a possibility for subsequent development of glassy alloys with compositions which can be used for structural materials.