Variability of poisson's ratio and enhanced ductility in amorphous metal
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Date
2013-05-01
Journal Title
Journal ISSN
Volume Title
Publisher
Wilye-V C H Verlag GMBH
Abstract
Ductile bulk metallic glass of composition 53.0Zr–18.7Cu–12.0Ni–16.3Al (at%) is plastically deformed under uniaxial compression and observed in situ by synchrotron high-energy X-ray diffraction. The diffraction patterns reveal the induced atomic strain is orientation dependent. At the onset of plastic deformation, the atomic strain in the compression direction saturates to a close-nearest-neighbor distance while atoms relax in the transverse direction. The ever increasing transverse atomic strain expresses in an augmentation of the apparent Poisson's ratio up to ν = 0.5, which is consistent with volume conservation. Contradicting phenomena from linear mechanics, such as the non-vanishing shear modulus at ν = 0.5 can be explained by the non-affine character of the deformation, giving rise to characteristics of a localized martensitic phase transformation. The findings explain the often-reported phenomena such as, the high Poisson's ratio values found in metallic glasses, the partially liquid character of the structure, the free volume increase and the Bauschinger effect. © 2013, Wiley-VCH Verlag GmbH & Co. KGaA
Description
Keywords
Glass, Atoms, Phase transformations, X-ray diffraction, X-ray lasers, Synchrotrons
Citation
Liss, K. -D., Qu, D. D., Yan, K., & Reid, M. (2013). Variability of poisson's ratio and enhanced ductility in mmorphous metal. Advanced Engineering Materials, 15(5), 347-351. doi:10.1002/adem.201200216