Influence of mutual substitution between La and Gd on the glass-forming ability of Al-Ni-La-Gd alloys

A series of Al100-a-bNia(La1-xGdx)b alloys, where a = 9-10, b = 4.5-5.5 and x = 0-1, were suction cast under identical conditions into a wedge-shaped copper mold for investigating the compositional dependence of glass-forming ability (GFA). The GFA of the ternary alloys, except for the optimal glass former (Al85.5Ni9.5La(Gd)5), is enhanced when a given rare earth element (La or Gd) is partially substituted by the other. The mutual substitution content between La and Gd for the optimal GFA increases with a decrease in Ni content. The enhancement of GFA by the mutual substitution between La and Gd was interpreted based on Miracle's model of atom packing efficiency.