Effects of Ag substitution for Fe on glass-forming ability, crystallization kinetics, and mechanical properties of Ni-free Zr-Cu-Al-Fe bulk metallic glasses

In present study, the effects of the substitution of Ag for Fe on the glass-forming ability (GFA), crystallization kinetics, and mechanical properties of Zr60Cu25Al10Fe5-xAgx (x = 0, 1, 2, 3, 4, and 5 at%) bulk metallic glasses (BMGs) were investigated. Under the same experimental conditions, the critical diameter for glass formation increased significantly by appropriately substituting Ag for Fe. The activation energies, including E-g, E-x, and E-p, all increased significantly, which indicated that Ag addition reduced the sensitivity of the amorphous alloys to temperature, as well as increased the energy barriers of atom rearrangements, nucleation and growth, i.e., the stability of the BMG enhanced. In addition, the plasticity of the alloys was enhanced thanks to the substitution. The plastic strain reached 3.7% when the content of Ag was 4 at%, which is nearly 10 times higher than the original composition (0.4%). (C) 2020 Elsevier B.V. All rights reserved.