The effect of layer thickness ratio on the plastic deformation mechanisms of nanoindented Ti/TiN nanolayered composite

Wei Yang, Georges Ayoub, Iman Salehinia, Bilal Mansoor, Hussein Zbib

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Molecular dynamics simulations were performed to identify the underlying deformation mechanisms controlling the plastic behavior of nanoindented nanoscale multilayered Ti/TiN. MD simulations were conducted on pure Ti and pure TiN as well as on four different layer-thickness ratios of Ti/TiN multilayers, Ti:TiN = 1, 2.5, 4, and 7.5. The Ti layer thickness varied from 2 nm to 15 nm while the TiN layer thickness is kept constant of 2 nm. The plastic deformation of nanoindented pure Ti was dominated by the formation of dislocation loops resulting from basal partial dislocations, while very few perfect dislocations that tie dislocation loops together were observed. The plastic deformation of nanoindented pure TiN was controlled by the activation of perfect dislocation propagation along the (111) plane that dissociates into two partials. Depending on the thickness ratio, either dislocation pile-up or single dislocation crossing through the interface was the controlling plastic deformation mechanism of nanoindented Ti/TiN multilayers. For metal layer thicknesses above 5 nm, significant dislocation pile-ups were observed at the interface of the multi-layered samples. The Ti/TiN multilayer with a thickness ratio of 1:1 with individual layer thickness of 2 nm exhibited the highest strain-hardening rate. At this length scale, the activation of dislocation sources requires very high stresses, and the single dislocation crossing process is the most dominant deformation mechanism. The initiation of plasticity in the TiN layer occurs at a high level of stress since there is no dislocation pile-up at the interface.

Original languageEnglish
Pages (from-to)488-498
Number of pages11
JournalComputational Materials Science
Volume154
DOIs
Publication statusPublished - 1 Nov 2018

Fingerprint

thickness ratio
Plastic Deformation
Dislocation
plastic deformation
Piles
Plastic deformation
Multilayers
Composite
composite materials
Composite materials
Chemical activation
Strain hardening
Plasticity
Molecular dynamics
piles
Metals
Multilayer
Plastics
Computer simulation
Activation

Keywords

  • Dislocations nucleation
  • Metals/ceramics multilayers
  • Molecular dynamics
  • Nanoindentation
  • Ti/TiN

ASJC Scopus subject areas

  • Computer Science(all)
  • Chemistry(all)
  • Materials Science(all)
  • Mechanics of Materials
  • Physics and Astronomy(all)
  • Computational Mathematics

Cite this

The effect of layer thickness ratio on the plastic deformation mechanisms of nanoindented Ti/TiN nanolayered composite. / Yang, Wei; Ayoub, Georges; Salehinia, Iman; Mansoor, Bilal; Zbib, Hussein.

In: Computational Materials Science, Vol. 154, 01.11.2018, p. 488-498.

Research output: Contribution to journalArticle

@article{b02395ca2cdc40b0826da9fea47364ab,
title = "The effect of layer thickness ratio on the plastic deformation mechanisms of nanoindented Ti/TiN nanolayered composite",
abstract = "Molecular dynamics simulations were performed to identify the underlying deformation mechanisms controlling the plastic behavior of nanoindented nanoscale multilayered Ti/TiN. MD simulations were conducted on pure Ti and pure TiN as well as on four different layer-thickness ratios of Ti/TiN multilayers, Ti:TiN = 1, 2.5, 4, and 7.5. The Ti layer thickness varied from 2 nm to 15 nm while the TiN layer thickness is kept constant of 2 nm. The plastic deformation of nanoindented pure Ti was dominated by the formation of dislocation loops resulting from basal partial dislocations, while very few perfect dislocations that tie dislocation loops together were observed. The plastic deformation of nanoindented pure TiN was controlled by the activation of perfect dislocation propagation along the (111) plane that dissociates into two partials. Depending on the thickness ratio, either dislocation pile-up or single dislocation crossing through the interface was the controlling plastic deformation mechanism of nanoindented Ti/TiN multilayers. For metal layer thicknesses above 5 nm, significant dislocation pile-ups were observed at the interface of the multi-layered samples. The Ti/TiN multilayer with a thickness ratio of 1:1 with individual layer thickness of 2 nm exhibited the highest strain-hardening rate. At this length scale, the activation of dislocation sources requires very high stresses, and the single dislocation crossing process is the most dominant deformation mechanism. The initiation of plasticity in the TiN layer occurs at a high level of stress since there is no dislocation pile-up at the interface.",
keywords = "Dislocations nucleation, Metals/ceramics multilayers, Molecular dynamics, Nanoindentation, Ti/TiN",
author = "Wei Yang and Georges Ayoub and Iman Salehinia and Bilal Mansoor and Hussein Zbib",
year = "2018",
month = "11",
day = "1",
doi = "10.1016/j.commatsci.2018.08.021",
language = "English",
volume = "154",
pages = "488--498",
journal = "Computational Materials Science",
issn = "0927-0256",
publisher = "Elsevier",

}

TY - JOUR

T1 - The effect of layer thickness ratio on the plastic deformation mechanisms of nanoindented Ti/TiN nanolayered composite

AU - Yang, Wei

AU - Ayoub, Georges

AU - Salehinia, Iman

AU - Mansoor, Bilal

AU - Zbib, Hussein

PY - 2018/11/1

Y1 - 2018/11/1

N2 - Molecular dynamics simulations were performed to identify the underlying deformation mechanisms controlling the plastic behavior of nanoindented nanoscale multilayered Ti/TiN. MD simulations were conducted on pure Ti and pure TiN as well as on four different layer-thickness ratios of Ti/TiN multilayers, Ti:TiN = 1, 2.5, 4, and 7.5. The Ti layer thickness varied from 2 nm to 15 nm while the TiN layer thickness is kept constant of 2 nm. The plastic deformation of nanoindented pure Ti was dominated by the formation of dislocation loops resulting from basal partial dislocations, while very few perfect dislocations that tie dislocation loops together were observed. The plastic deformation of nanoindented pure TiN was controlled by the activation of perfect dislocation propagation along the (111) plane that dissociates into two partials. Depending on the thickness ratio, either dislocation pile-up or single dislocation crossing through the interface was the controlling plastic deformation mechanism of nanoindented Ti/TiN multilayers. For metal layer thicknesses above 5 nm, significant dislocation pile-ups were observed at the interface of the multi-layered samples. The Ti/TiN multilayer with a thickness ratio of 1:1 with individual layer thickness of 2 nm exhibited the highest strain-hardening rate. At this length scale, the activation of dislocation sources requires very high stresses, and the single dislocation crossing process is the most dominant deformation mechanism. The initiation of plasticity in the TiN layer occurs at a high level of stress since there is no dislocation pile-up at the interface.

AB - Molecular dynamics simulations were performed to identify the underlying deformation mechanisms controlling the plastic behavior of nanoindented nanoscale multilayered Ti/TiN. MD simulations were conducted on pure Ti and pure TiN as well as on four different layer-thickness ratios of Ti/TiN multilayers, Ti:TiN = 1, 2.5, 4, and 7.5. The Ti layer thickness varied from 2 nm to 15 nm while the TiN layer thickness is kept constant of 2 nm. The plastic deformation of nanoindented pure Ti was dominated by the formation of dislocation loops resulting from basal partial dislocations, while very few perfect dislocations that tie dislocation loops together were observed. The plastic deformation of nanoindented pure TiN was controlled by the activation of perfect dislocation propagation along the (111) plane that dissociates into two partials. Depending on the thickness ratio, either dislocation pile-up or single dislocation crossing through the interface was the controlling plastic deformation mechanism of nanoindented Ti/TiN multilayers. For metal layer thicknesses above 5 nm, significant dislocation pile-ups were observed at the interface of the multi-layered samples. The Ti/TiN multilayer with a thickness ratio of 1:1 with individual layer thickness of 2 nm exhibited the highest strain-hardening rate. At this length scale, the activation of dislocation sources requires very high stresses, and the single dislocation crossing process is the most dominant deformation mechanism. The initiation of plasticity in the TiN layer occurs at a high level of stress since there is no dislocation pile-up at the interface.

KW - Dislocations nucleation

KW - Metals/ceramics multilayers

KW - Molecular dynamics

KW - Nanoindentation

KW - Ti/TiN

UR - http://www.scopus.com/inward/record.url?scp=85051667052&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85051667052&partnerID=8YFLogxK

U2 - 10.1016/j.commatsci.2018.08.021

DO - 10.1016/j.commatsci.2018.08.021

M3 - Article

AN - SCOPUS:85051667052

VL - 154

SP - 488

EP - 498

JO - Computational Materials Science

JF - Computational Materials Science

SN - 0927-0256

ER -