Over the last decade, a significant advancement has been made in exploring multicomponent glass-forming metallic alloys with substantially sluggish crystallization kinetics, which resulted in the development of numerous bulk-metallic glasses (BMGs) with a thickness of several millimeters or even centimeters. This progress makes the applications of metallic glasses as structural materials become a reality. [1] The BMGs have outstanding mechanical properties, such as the high strength of up to 5 GPa, [2] large elastic deformation limit of around 2 %, [1] as well as good fatigue properties, [3][4][5][6] and, thus, they may be critical for advanced structural applications. However, the BMGs exhibit very limited plasticity, which is generally less than 2 % of the plastic strain in compression and almost zero in tension, and subsequent premature fracture. Undoubtedly, the poor plasticity and catastrophic fracture endanger the structural safety and hinder the extensive applications of the BMGs. The unfavorable mechanical behaviors/properties of the BMGs are imputed to their highly-localized inhomogeneous deformation.At low temperatures (e.g., room temperature) and high strain rates, the BMGs exhibit the inhomogeneous deformation, which is limited to highly-localized narrow regions, i.e., shear bands. [7] The formation of the shear bands affects plastic-flow and fracture behaviors substantially. [7][8][9][10] The excessive propagation of individual shear bands causes the premature failure. Various strategies have been developed to improve BMGs' ductility such as the insertion of crystalline phases or pores into the amorphous matrix, which forms crystalline or porosity/amorphous matrix composites. [11][12][13][14][15] These BMG composites display the improved ductility that results from the multiplication of shear bands.Recently, Das et al. [16] reported a new class of Cu 47.5 -Zr 47.5 Al 5 (atomic percent, at.-%) BMGs that exhibit an obvious work-hardening behavior and large ductility. These extraordinary mechanical behaviors/properties are attractive, which are different from those of common BMGs that show work softening and poor plasticity. The origin of this unique work-hardening behavior is still in debate. [16][17][18][19][20] In this paper, we re-examined the mechanical behavior of the work-hardening Cu 47.5 Zr 47.5 Al 5 in quasistatic compression and compared it with that of a common Zr 55 Ni 5 Al 10 Cu 30 BMG. It is expected that the present work can provide insight to the relationship between the plastic flow and shear-banding behavior of the BMGs and it may be helpful for improving the ductility of the BMGs. Figure 1 shows the engineering stress-strain curves of the Cu 47.5 Zr 47.5 Al 5 and Zr 55 Ni 5 Al 10 Cu 30 BMGs in the quasistatic compression at a strain rate of 2 × 10 -4 s -1 . From the engineering stress-strain curves, we derive the yield strength, compressive strength, and plastic strain for both the BMGs, and the results are listed in Table 1. It is noted that the compression tests for the Cu 47.5 Zr ...