Glass-forming ability and fragility of RE55Al25Co20 (RE = Ce, Pr, Nd, Sm, Gd) alloys

The glass-forming ability (GFA) of RE55Al25Co20 (RE = Ce, Pr, Nd, Sm, Gd) alloys ranks as follows: Ce55Al25Co20 < Pr55Al25Co20 and Nd55Al25Co20 < Sm55Al25Co20 and Gd55Al25Co20. Only Sm55Al25Co20 and Gd55Al25Co20 alloys show wholly amorphous structures when the alloys are cast into rods up to 2 mm in diameter. A comparison study shows that the Sm55Al25Co20 alloy exhibits the smaller difference in Gibbs free energy (ΔG1−x(Tg)) and the stronger fragility, which are consistent with the higher GFA for this alloy.