Bulk metallic glass formation in Cu–Zr–Ti ternary system

The formation of bulk metallic glasses (BMG) in the Cu-rich Cu–Zr–Ti ternary system is studied by using the ‘e/a-variant line criterion’. Three such lines, (Cu9Zr4)1−xTix, (Cu61.8Zr38.2)1−xTix and (Cu56Zr44)1−xTix, are defined in the Cu–Zr–Ti system by linking three binary compositions Cu9Zr4, Cu61.8Zr38.2 and Cu56Zr44 to the third element Ti. The binary compositions Cu9Zr4, Cu61.8Zr38.2 and Cu56Zr44 correspond to specific Cu–Zr binary clusters. BMGs are obtained by copper mould suction casting method with Ti contents of 7.5–15 at.%, 7.5–12.5 at.% and 5–12 at.%, respectively along the (Cu9Zr4)1−x Tix, (Cu61.8Zr38.2)1−xTix and (Cu56Zr44)1−xTix lines. The BMGs on each composition line manifest decreased thermal stabilities and glass forming abilities (GFAs) with increasing Ti contents. The maximum GFA appears at Cu64Zr28.5Ti7.5, with characteristic thermal parameters of Tg = 736 K, Tx = 769 K, Tg/Tl = 0.627 and γ = 0.403, which are all superior to those reported for the known Cu60Zr30Ti10 BMG.