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

Abstract 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, (Cu 9 Zr 4 ) 1− x Ti x , (Cu 61.8 Zr 38.2 ) 1− x Ti x and (Cu 56 Zr 44 ) 1− x Ti x , are defined in the Cu–Zr–Ti system by linking three binary compositions Cu 9 Zr 4 , Cu 61.8 Zr 38.2 and Cu 56 Zr 44 to the third element Ti. The binary compositions Cu 9 Zr 4 , Cu 61.8 Zr 38.2 and Cu 56 Zr 44 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 (Cu 9 Zr 4 ) 1− x Ti x , (Cu 61.8 Zr 38.2 ) 1− x Ti x and (Cu 56 Zr 44 ) 1− x Ti x 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 Cu 64 Zr 28.5 Ti 7.5 , with characteristic thermal parameters of T g = 736 K, T x = 769 K, T g / T l = 0.627 and γ = 0.403, which are all superior to those reported for the known Cu 60 Zr 30 Ti 10 BMG.