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

Abstract

New Cu-based bulk glassy alloys of Cu-Zr-Ti system were formed by copper mold casting. The maximum diameter is 4 mm for the Cu60Zr30Ti10 alloy. The addition of Ti to Cu60Zr40 resulted in an increase in the glass-forming ability (GFA). As the Ti content increases, the glass transition temperature (Tg), crystallization temperature (Tx) and temperature interval of supercooled liquid region ΔTx (= Tx - Tg) decrease, while the liquidus temperature (T1) has a minimum of 1127 K around 20%Ti, leading to a maximum Tg/T1 of 0.63 in the vicinity of 20 at%Ti. The high GFA of the Cu-based alloys was obtained at the compositions with high Tg/T1. The bulk glassy Cu60Zr30Ti10 alloy exhibits Vickers hardness of 660, Young's modulus of 114 GPa, fracture strength of 2150 MPa and compressive plastic elongation of 1.7 %. The finding of the Cu-based bulk glassy alloy with high Tg/T1 above 0.60. high fracture strength above 2000 MPa and distinct plastic elongation is encouraging for future development as a new type of bulk glassy alloys which can be used for structural materials.