Ideal elasto-plastic behavior in torsional deformation of Zr44Ti11Cu10Ni10Be25 bulk metallic glass

Large plastic strain can be attained in Zr44Ti11Cu10Ni10Be25 bulk metallic glass below the glass transition temperature by applying the free-end torsion method. The initial part of the deformation of the metallic glass can be accurately described by a homogeneous ideal elasto-plastic model. Deviation from the ideal behavior occurs when plastic shear deformation becomes macroscopically inhomogeneous and longitudinal shear bands appear on the surface in addition to shear bands perpendicular to the torsion axis. Samples with multiple sets of shear bands fracture after substantially higher macroscopic shear deformation.

► Controlled plastic deformation was achieved in BMGs by free-end torsion method. ► Initial part of the deformation shows ideal elasto-plastic behavior in BMGs. ► Strain softening was observed in a latter stage of plastic deformation. ► Large plastic strain was reached in tests showing transition in shear banding.