The role of minor alloying in the plasticity of bulk metallic glasses

Abstract

Micro- or minor alloying of metallic glasses is of technological interest. An originally ductile Pd-based monolithic bulk metallic glass (Pd${}_{40}$Ni${}_{40}$P${}_{20}$) was selectively manipulated by additions of Fe or Co. The alloying effects were extreme, showing either exceptional ductility upon Co addition or immediate catastrophic failure upon Fe addition when tested under uniaxial compression or 3-point bending. The amorphous structure was characterized prior to deformation with respect to its medium-range order (MRO) using variable resolution fluctuation electron microscopy (VR-FEM). We observe striking differences in the MRO between the ductile and brittle metallic glasses, with the ductile glasses exhibiting a rich structural diversity and MRO correlation lengths up to 6 nm. The MRO heterogeneity seems to enable easier shear banding and hence enhance the deformability.

References in corpus (4)

• On the shear-affected zone of shear bands in bulk metallic glasses
• Real space information from Fluctuation electron microscopy: Applications to amorphous silicon
• What renders bulk metallic glass ductile/brittle? -- new insight from the medium-range order
• Structural Heterogeneity, Ductility, and Glass Forming Ability of Zr-Based Metallic Glasses

Cited by in corpus (2)

• Impact of severe plastic deformation on the relaxation of glassy and supercooled liquid states of amorphous Pd${}_{40}$Ni${}_{40}$P${}_{20}$
• Plasmon energy losses in shear bands of metallic glass