Cyclic hardening of metallic glasses under hertzian contacts: Experiments and STZ dynamics simulations

C. E. Packard; E. R. Homer; N. Al-Aqeeli; C. A. Schuh

doi:10.1080/14786430903352664

Cyclic hardening of metallic glasses under hertzian contacts: Experiments and STZ dynamics simulations

C. E. Packard, E. R. Homer, N. Al-Aqeeli, C. A. Schuh

King Fahd University of Petroleum & Minerals

Research output: Contribution to journal › Article › peer-review

74 Scopus citations

Abstract

A combined program of experiments and simulations is used to study the problem of cyclic indentation loading on metallic glasses. The experiments use a spherical nanoindenter tip to study shear band formation in three glasses (two based on Pd and one on Fe), after subjecting the glass to cycles of load in the nominal elastic range. In all three glasses, such elastic cycles lead to significant increases in the load required to subsequently trigger the first shear band. This cyclic hardening occurs progressively over several cycles, but eventually saturates. The effect requires cycles of sufficient amplitude and is not induced by sustained loading alone. The simulations employed a new shear transformation zone (STZ) dynamics code to reveal the local STZ operations that occur beneath an indenter during cycling. These results reveal a plausible mechanism for the observed cyclic hardening: local regions of confined microplasticity can develop progressively over several cycles, without being detectable in the global load-displacement response. It is inferred that significant structural change must attend such microplasticity, leading to hardening of the glass.

Original language	English
Pages (from-to)	1373-1390
Number of pages	18
Journal	Philosophical Magazine
Volume	90
Issue number	10
DOIs	https://doi.org/10.1080/14786430903352664
State	Published - Mar 2010

Bibliographical note

Funding Information:
This work was supported by the Office of Naval Research under Grant No. N00014-08-10312. The authors would like to thank Dr Y. Li (National University of Singapore) and Dr J. Shen (Harbin Institute of Technology) for providing the glasses used in this work. Additionally, CEP would like to thank Lisa Witmer for assistance with data collection. ERH gratefully acknowledges financial support through the National Defense Science and Engineering Graduate (NDSEG) fellowship with support from the Army Research Office (ARO). NA wishes to express gratitude to King Fahd University of Petroleum & Minerals (KFUPM) for their financial support.

Keywords

Cyclic deformation
Fatigue
Metallic glass
Nanoindentation

ASJC Scopus subject areas

Condensed Matter Physics

Access to Document

10.1080/14786430903352664

Cite this

@article{1045c3f4b0874504b9cc7b1ea56e0ff7,

title = "Cyclic hardening of metallic glasses under hertzian contacts: Experiments and STZ dynamics simulations",

abstract = "A combined program of experiments and simulations is used to study the problem of cyclic indentation loading on metallic glasses. The experiments use a spherical nanoindenter tip to study shear band formation in three glasses (two based on Pd and one on Fe), after subjecting the glass to cycles of load in the nominal elastic range. In all three glasses, such elastic cycles lead to significant increases in the load required to subsequently trigger the first shear band. This cyclic hardening occurs progressively over several cycles, but eventually saturates. The effect requires cycles of sufficient amplitude and is not induced by sustained loading alone. The simulations employed a new shear transformation zone (STZ) dynamics code to reveal the local STZ operations that occur beneath an indenter during cycling. These results reveal a plausible mechanism for the observed cyclic hardening: local regions of confined microplasticity can develop progressively over several cycles, without being detectable in the global load-displacement response. It is inferred that significant structural change must attend such microplasticity, leading to hardening of the glass.",

keywords = "Cyclic deformation, Fatigue, Metallic glass, Nanoindentation",

author = "Packard, \{C. E.\} and Homer, \{E. R.\} and N. Al-Aqeeli and Schuh, \{C. A.\}",

note = "Funding Information: This work was supported by the Office of Naval Research under Grant No. N00014-08-10312. The authors would like to thank Dr Y. Li (National University of Singapore) and Dr J. Shen (Harbin Institute of Technology) for providing the glasses used in this work. Additionally, CEP would like to thank Lisa Witmer for assistance with data collection. ERH gratefully acknowledges financial support through the National Defense Science and Engineering Graduate (NDSEG) fellowship with support from the Army Research Office (ARO). NA wishes to express gratitude to King Fahd University of Petroleum \& Minerals (KFUPM) for their financial support.",

year = "2010",

month = mar,

doi = "10.1080/14786430903352664",

language = "English",

volume = "90",

pages = "1373--1390",

journal = "Philosophical Magazine",

issn = "1478-6435",

publisher = "Taylor and Francis Ltd.",

number = "10",

}

TY - JOUR

T1 - Cyclic hardening of metallic glasses under hertzian contacts

T2 - Experiments and STZ dynamics simulations

AU - Packard, C. E.

AU - Homer, E. R.

AU - Al-Aqeeli, N.

AU - Schuh, C. A.

N1 - Funding Information: This work was supported by the Office of Naval Research under Grant No. N00014-08-10312. The authors would like to thank Dr Y. Li (National University of Singapore) and Dr J. Shen (Harbin Institute of Technology) for providing the glasses used in this work. Additionally, CEP would like to thank Lisa Witmer for assistance with data collection. ERH gratefully acknowledges financial support through the National Defense Science and Engineering Graduate (NDSEG) fellowship with support from the Army Research Office (ARO). NA wishes to express gratitude to King Fahd University of Petroleum & Minerals (KFUPM) for their financial support.

PY - 2010/3

Y1 - 2010/3

N2 - A combined program of experiments and simulations is used to study the problem of cyclic indentation loading on metallic glasses. The experiments use a spherical nanoindenter tip to study shear band formation in three glasses (two based on Pd and one on Fe), after subjecting the glass to cycles of load in the nominal elastic range. In all three glasses, such elastic cycles lead to significant increases in the load required to subsequently trigger the first shear band. This cyclic hardening occurs progressively over several cycles, but eventually saturates. The effect requires cycles of sufficient amplitude and is not induced by sustained loading alone. The simulations employed a new shear transformation zone (STZ) dynamics code to reveal the local STZ operations that occur beneath an indenter during cycling. These results reveal a plausible mechanism for the observed cyclic hardening: local regions of confined microplasticity can develop progressively over several cycles, without being detectable in the global load-displacement response. It is inferred that significant structural change must attend such microplasticity, leading to hardening of the glass.

AB - A combined program of experiments and simulations is used to study the problem of cyclic indentation loading on metallic glasses. The experiments use a spherical nanoindenter tip to study shear band formation in three glasses (two based on Pd and one on Fe), after subjecting the glass to cycles of load in the nominal elastic range. In all three glasses, such elastic cycles lead to significant increases in the load required to subsequently trigger the first shear band. This cyclic hardening occurs progressively over several cycles, but eventually saturates. The effect requires cycles of sufficient amplitude and is not induced by sustained loading alone. The simulations employed a new shear transformation zone (STZ) dynamics code to reveal the local STZ operations that occur beneath an indenter during cycling. These results reveal a plausible mechanism for the observed cyclic hardening: local regions of confined microplasticity can develop progressively over several cycles, without being detectable in the global load-displacement response. It is inferred that significant structural change must attend such microplasticity, leading to hardening of the glass.

KW - Cyclic deformation

KW - Fatigue

KW - Metallic glass

KW - Nanoindentation

UR - https://www.scopus.com/pages/publications/77951160446

U2 - 10.1080/14786430903352664

DO - 10.1080/14786430903352664

M3 - Article

AN - SCOPUS:77951160446

SN - 1478-6435

VL - 90

SP - 1373

EP - 1390

JO - Philosophical Magazine

JF - Philosophical Magazine

IS - 10

ER -

Cyclic hardening of metallic glasses under hertzian contacts: Experiments and STZ dynamics simulations

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

Fingerprint

Cite this