Glass forming ability and crystallization behavior of Al–Ni–RE metallic glasses

Abstract

Atomic size may change due to the interaction between different elements when pure metals are synthesized into alloys. In present paper, the effective atomic radii instead of the nominal radii were introduced in the cluster line method to predict the optimum glass forming compositions in Al-based Al–Ni–RE (RE = La, Y, Ce, Gd, Dy) systems. Wedge-shaped samples of the alloys were suction cast under well-controlled condition to experimentally determine the dependence of the glass forming ability (GFA) on the composition. It is found that such a modification to the method makes the prediction very close to the experimental results. When the effective atomic radii are used to calculate the topological instability parameter originally proposed by Egami and Waseda, λ′, the λ′ corresponding to the best GFA in each Al–Ni–RE system linearly changes with the radius of the RE element. Meantime, the onset temperature of crystallization and mixing enthalpy linearly increase with the λ′.