Open AccessHardening of shear band in metallic glass
Author(s) -
J. G. Wang,
Yongbin Hu,
Ping Guan,
Kaikai Song,
Linghua Wang,
G. Wang,
Pan Ye,
Baran Sarac,
J. Eckert
Publication year - 2017
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/s41598-017-07669-9
Subject(s) - materials science , amorphous metal , hardening (computing) , icosahedral symmetry , hydrostatic pressure , shear band , hardenability , strain hardening exponent , composite material , shear (geology) , brittleness , mechanics , crystallography , alloy , physics , layer (electronics) , chemistry
Strain hardening, originating from defects such as the dislocation, avails conventional metals of high engineering reliability in applications. However, the hardenability of metallic glass is a long-standing concern due to the lack of similar defects. In this work, we carefully examine the stress-strain relationship in three bulk monolithic metallic glasses. The results show that hardening is surely available in metallic glasses if the effective load-bearing area is considered instantly. The hardening is proposed to result from the remelting and ensuing solidification of the shear-band material under a hydrostatic pressure imposed by the normal stress during the shear banding event. This applied-pressure quenching densifies the metallic glass by discharging the free volume. On the other hand, as validated by molecular dynamics simulations, the pressure promotes the icosahedral short-range order. The densification and icosahedral clusters both contribute to the increase of the shear strength and therefore the hardening in metallic glasses.