Tensile deformation behaviors and damping properties of small-sized Cu–Zr–Al metallic glasses

Uniaxial tensile tests were performed on micron-sized Cu–Zr–Al metallic glassy wires (MGWs) to investigate the deformation behaviors. It is found that the MGWs exhibit unusual nonlinear deformation behavior with irreversible elongation, and our analysis indicates that this nonlinear deformation is related to the formation of sub-nanometer voids coalesced from flow defects under tensile stress. MGWs at micrometer scale exhibit a lower Young’s modulus than that of the bulk. The strong structure relaxation leads to the increase of the modulus when heating up the MGWs. The internal friction shows that the MGWs become a viscous state above glass transition temperature.

The Young’s modulus of the MGWs is about 20% smaller than that of the bulk (about 87 GPa). Generally, the free volume in the liquid states is excessive compared to that in the glassy states. Indeed, it can be frozen if extremely fast quenching is realized. The formation of the MGWs was performed under a high strain rate and ultrahigh cooling rate due to the extremely small heat capacity. Therefore, the hyper-excess free volumes in the MGWs can be highly expected.Figure optionsDownload as PowerPoint slideHighlights
► Characterization studies like SEM, DSC, DMA, and tensile tests have been carried out.
► Cu–Zr–Al metallic glassy wires show a nonlinear deformation.
► The Young’s modulus is much smaller than that of the bulk.
► Strong structure relaxation leads to an increase of modulus.