Fracture toughness trends of modulus-matched TiN/(Cr,Al)N thin film superlattices

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Fracture toughness trends of modulus-matched TiN/(Cr,Al)N thin film superlattices. / Buchinger, J.; Wagner, A.; Chen, Zhuo et al.
In: Acta materialia, Vol. 202.2021, No. 1 January, 01.01.2021, p. 376-386.

Research output: Contribution to journalArticleResearchpeer-review

Harvard

Buchinger, J, Wagner, A, Chen, Z, Zhang, Z, Holec, D, Mayrhofer, PH & Bartosik, M 2021, 'Fracture toughness trends of modulus-matched TiN/(Cr,Al)N thin film superlattices', Acta materialia, vol. 202.2021, no. 1 January, pp. 376-386. https://doi.org/10.1016/j.actamat.2020.10.068

APA

Buchinger, J., Wagner, A., Chen, Z., Zhang, Z., Holec, D., Mayrhofer, P. H., & Bartosik, M. (2021). Fracture toughness trends of modulus-matched TiN/(Cr,Al)N thin film superlattices. Acta materialia, 202.2021(1 January), 376-386. https://doi.org/10.1016/j.actamat.2020.10.068

Vancouver

Buchinger J, Wagner A, Chen Z, Zhang Z, Holec D, Mayrhofer PH et al. Fracture toughness trends of modulus-matched TiN/(Cr,Al)N thin film superlattices. Acta materialia. 2021 Jan 1;202.2021(1 January):376-386. Epub 2020 Nov 1. doi: 10.1016/j.actamat.2020.10.068

Author

Buchinger, J. ; Wagner, A. ; Chen, Zhuo et al. / Fracture toughness trends of modulus-matched TiN/(Cr,Al)N thin film superlattices. In: Acta materialia. 2021 ; Vol. 202.2021, No. 1 January. pp. 376-386.

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@article{4431f4d5c54a40fa9ad9243865d3192a,
title = "Fracture toughness trends of modulus-matched TiN/(Cr,Al)N thin film superlattices",
abstract = "Through superlattice (SL) architectures, the hardness as well as the fracture toughness of ceramic thin films can be enhanced. The hardness-related SL effect is reasonably well understood, however, the mechanisms driving the toughness-enhancing effect are still partially unexplored. To isolate the effect of the lattice mismatch from the elastic moduli mismatch on the toughness-related properties, we designed TiN/Cr 0.37Al 0.63N superlattices, in which the involved layers have effectively identical elastic moduli, but sizeably different lattice parameters. Micromechanical bending tests show an enhanced fracture toughness K IC of the SLs (2.5±0.1 MPa√m) compared with monolithic TiN (2.0±0.1 MPa√m) and Cr 0.37Al 0.63N (1.3±0.1 MPa√m) with only a weak bilayer period (Λ) dependence. Superimposing an analytical model based on continuum mechanics on the experimental data, we demonstrate that, at low Λ, the nanolayers within the SL exhibit strong coherency strains, as misfit dislocation formation is energetically unfavourable. With increasing layer thicknesses, misfit dislocations start to form in the two layer materials – first in Cr 0.37Al 0.63N and slightly Λ-shifted in TiN. The associated evolution of coherency strains in the TiN and Cr 0.37Al 0.63N layers causes the observed bilayer-period-dependent toughness enhancement beyond the constituent materials. Supporting structural, morphological, chemical, and mechanical analyses are provided by X-ray diffraction, electron microscopy techniques, and nanoindentation. ",
author = "J. Buchinger and A. Wagner and Zhuo Chen and Zaoli Zhang and David Holec and Mayrhofer, {Paul Heinz} and Matthias Bartosik",
note = "Publisher Copyright: {\textcopyright} 2020 Acta Materialia Inc.",
year = "2021",
month = jan,
day = "1",
doi = "10.1016/j.actamat.2020.10.068",
language = "English",
volume = "202.2021",
pages = "376--386",
journal = "Acta materialia",
issn = "1359-6454",
publisher = "Elsevier",
number = "1 January",

}

RIS (suitable for import to EndNote) - Download

TY - JOUR

T1 - Fracture toughness trends of modulus-matched TiN/(Cr,Al)N thin film superlattices

AU - Buchinger, J.

AU - Wagner, A.

AU - Chen, Zhuo

AU - Zhang, Zaoli

AU - Holec, David

AU - Mayrhofer, Paul Heinz

AU - Bartosik, Matthias

N1 - Publisher Copyright: © 2020 Acta Materialia Inc.

PY - 2021/1/1

Y1 - 2021/1/1

N2 - Through superlattice (SL) architectures, the hardness as well as the fracture toughness of ceramic thin films can be enhanced. The hardness-related SL effect is reasonably well understood, however, the mechanisms driving the toughness-enhancing effect are still partially unexplored. To isolate the effect of the lattice mismatch from the elastic moduli mismatch on the toughness-related properties, we designed TiN/Cr 0.37Al 0.63N superlattices, in which the involved layers have effectively identical elastic moduli, but sizeably different lattice parameters. Micromechanical bending tests show an enhanced fracture toughness K IC of the SLs (2.5±0.1 MPa√m) compared with monolithic TiN (2.0±0.1 MPa√m) and Cr 0.37Al 0.63N (1.3±0.1 MPa√m) with only a weak bilayer period (Λ) dependence. Superimposing an analytical model based on continuum mechanics on the experimental data, we demonstrate that, at low Λ, the nanolayers within the SL exhibit strong coherency strains, as misfit dislocation formation is energetically unfavourable. With increasing layer thicknesses, misfit dislocations start to form in the two layer materials – first in Cr 0.37Al 0.63N and slightly Λ-shifted in TiN. The associated evolution of coherency strains in the TiN and Cr 0.37Al 0.63N layers causes the observed bilayer-period-dependent toughness enhancement beyond the constituent materials. Supporting structural, morphological, chemical, and mechanical analyses are provided by X-ray diffraction, electron microscopy techniques, and nanoindentation.

AB - Through superlattice (SL) architectures, the hardness as well as the fracture toughness of ceramic thin films can be enhanced. The hardness-related SL effect is reasonably well understood, however, the mechanisms driving the toughness-enhancing effect are still partially unexplored. To isolate the effect of the lattice mismatch from the elastic moduli mismatch on the toughness-related properties, we designed TiN/Cr 0.37Al 0.63N superlattices, in which the involved layers have effectively identical elastic moduli, but sizeably different lattice parameters. Micromechanical bending tests show an enhanced fracture toughness K IC of the SLs (2.5±0.1 MPa√m) compared with monolithic TiN (2.0±0.1 MPa√m) and Cr 0.37Al 0.63N (1.3±0.1 MPa√m) with only a weak bilayer period (Λ) dependence. Superimposing an analytical model based on continuum mechanics on the experimental data, we demonstrate that, at low Λ, the nanolayers within the SL exhibit strong coherency strains, as misfit dislocation formation is energetically unfavourable. With increasing layer thicknesses, misfit dislocations start to form in the two layer materials – first in Cr 0.37Al 0.63N and slightly Λ-shifted in TiN. The associated evolution of coherency strains in the TiN and Cr 0.37Al 0.63N layers causes the observed bilayer-period-dependent toughness enhancement beyond the constituent materials. Supporting structural, morphological, chemical, and mechanical analyses are provided by X-ray diffraction, electron microscopy techniques, and nanoindentation.

UR - http://www.scopus.com/inward/record.url?scp=85096192228&partnerID=8YFLogxK

U2 - 10.1016/j.actamat.2020.10.068

DO - 10.1016/j.actamat.2020.10.068

M3 - Article

VL - 202.2021

SP - 376

EP - 386

JO - Acta materialia

JF - Acta materialia

SN - 1359-6454

IS - 1 January

ER -