Localized deformation of a Cu_46.25Zr_45.25Al_7.5Er₁bulk metallic glass

Abstract

Using the cavity model and the concept of the plastic-hardening modulus, a simple relationship was established between the size of an indent and the size of a semi-spherical-shell softening zone. Indentation experiments of a Cu46.25Zr45.25Al7.5Er1 bulk-metallic glass (BMG) were performed over a range of indentation loads from 500 to 4000 mN, using a Vickers indenter. The indentation hardness decreased slightly with the increase in the indentation load from 5.21 GPa at an indentation load of 500 mN to 4.66 GPa at an indentation load of 4000 mN. The evolution of shear bands underneath the indentation was studied using an interface-bonded BMG sample. Shear bands of a semi-spherical-shell shape and a line-shape were observed underneath the indentation. The dependence of the size of the shear-banding zone on the size of the indent was examined, which qualitatively supported the analytical model. The inter-banding spacing decreased with the increase in the indentation load, associated with the release of the stored strain energy.

Indentation plastic work and large compression plasticity in in situ nanocrystallized Zr62Cu18Ni10Al10 bulk metallic glass

“…It should be noted that the values of U pl /U tot shown in Fig. 4(b) are in agreement with those reported for Zr 50 Cu 40 Al 10 (U pl /U tot ∼ 0.6 [27]) and Cu 46.25 Zr 45.25 Al 7.5 Er 1 BMG (U pl /U tot ∼ 0.7 [28]) and clearly larger than for brittle Fe-based BMG (U pl /U tot ∼ 0.37 [19]). In fact, the ratio U pl /U tot has been sometimes used to characterize the mechanical behavior of brittle materials which are often difficult to test using macroscopic tensile tests [29].…”

Brittle-Ductile Transition in Laser 3D Printing of Fe-Based Bulk Metallic Glass Composites

“…It can be seen from Figure 7b that the plasticity index U p /U t increases gradually with increasing α-Fe phase. The values of U p /U t with different α-Fe phases are above 0.8, which is close to the Ti 40 Zr 10 Cu 38 Pd 12 [27] and Cu 46.25 Zr 45.25 Al 7.5 Er 1 [31] BMGs, indicating that the printed Fe-based BMGs have intrinsic plasticity thanks to the existence of α-Fe phase.…”

Revelation of the effect of structural heterogeneity on microplasticity in bulk metallic-glasses

“…In the previous indentation studies of BMGs, the experimental revelation of the subsurface shear-band structures has been attempted using different approaches, 12,14,18,34,35 which entails the Vickers indentation on a bonded interface 14 plate. 12,18,34 Based on the experimental results, it was found that the pattern of the shear bands exposed on the surface of observation generally matched the predictions of the continuum theories well at the macroscopic scale.…”