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Three‐dimensional imaging of shear bands in bulk metallic glass composites
Author(s) -
HUNTER A.H.,
ARAULLOPETERS V.,
GIBBONS M.,
RESTREPO O.D.,
NIEZGODA S.R.,
WINDL W.,
FLORES K.M.,
HOFMANN D.C.,
MARQUIS E.A.
Publication year - 2016
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/jmi.12443
Subject(s) - materials science , amorphous metal , composite material , nucleation , shear (geology) , metal , shear band , composite number , ductility (earth science) , alloy , metallurgy , thermodynamics , creep , physics
Summary The mechanism of the increase in ductility in bulk metallic glass matrix composites over monolithic bulk metallic glasses is to date little understood, primarily because the interplay between dislocations in the crystalline phase and shear bands in the glass could neither be imaged nor modelled in a validated way. To overcome this roadblock, we show that shear bands can be imaged in three dimensions by atom probe tomography from density variations in the reconstructed atomic density, which density‐functional theory suggests being a local‐work function effect. Imaging of near‐interface shear bands in Ti 48 Zr 20 V 12 Cu 5 Be 15 bulk metallic glass matrix composite permits measurement of their composition, thickness, branching and interactions with the dendrite interface. These results confirm that shear bands here nucleate from stress concentrations in the glass due to intense, localized plastic deformation in the dendrites rather than intrinsic structural inhomogeneities.