EFFECT OF Gd ADDITION ON THE GLASS FORMING ABILITY AND MECHANICAL PROPERTIES IN A Zr–BASED BULK AMORPHOUS ALLOY

The glass forming ability (GFA) of a newly developed Zr_50.7Cu₂₈Ni₉Al_12.3 alloy can be improved by minor addition of Gd element, for example, the amorphous alloy Zr_50.7Cu₂₈Ni₉Al_12.3 has a critical diameter of 14 mm, but the alloy added by 1%Gd (atomic fraction), (Zr_50.7Cu₂₈Ni₉Al_12.3)₉₉Gd₁,
has 16 mm critical diameter. However, the Gd addition decreases the fracture strength and plastic strain under compressive condition. Meanwhile, with Gd addition increasing, the fracture mode transforms from pure shear to shear with hysterical failure. A combination of vein pattern and nanoscale corrugations can be clearly observed on the fracture surfaces of the alloys with Gd addition.