TY - JOUR
T1 - Variability of Poisson's ratio and enhanced ductility in amorphous metal
AU - Liss, Klaus Dieter
AU - Qu, Dongdong
AU - Yan, Kun
AU - Reid, Mark
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/5
Y1 - 2013/5
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=84877277210&partnerID=8YFLogxK
U2 - 10.1002/adem.201200216
DO - 10.1002/adem.201200216
M3 - 文章
AN - SCOPUS:84877277210
VL - 15
SP - 347
EP - 351
JO - Advanced Engineering Materials
JF - Advanced Engineering Materials
SN - 1438-1656
IS - 5
ER -