Effect of Ni–Al atomic ratio on glass formation in La–Al–Cu–Ni bulk metallic glasses

Glass forming ability (GFA) and thermal properties were investigated for La62Al14(Cu1−xNix)24 (x = 0.2, 0.4, 0.6 and 0.8) bulk metallic glasses (BMGs). The experimental results show that in the La-based La–Al–(Cu–Ni) pseudo-ternary system, optimum glass formation actually occurs at the Ni:Al ratio of 1:1. It has been found that the GFA is much better in the range of unstable intermetallic compound (AlNi) than that of adjacent stable intermetallic compound (AlNi3). The asymmetry of negative heat of mixing between the atomic pairs of La–Cu and La–Ni, Al–Cu and Al–Ni is also considered as another influencing factor of GFA. It might be an effective way to develop and design BMGs by adjusting the Ni–Al atomic ratio in Al–Ni-contained alloy systems.