liu.seSök publikationer i DiVA
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Strategy for simultaneously increasing both hardness and toughness in ZrB2-rich Zr1-xTaxBy thin films
Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
Visa övriga samt affilieringar
2019 (Engelska)Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 37, nr 3, artikel-id 031506Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Refractory transition-metal diborides exhibit inherent hardness. However, this is not always sufficient to prevent failure in applications involving high mechanical and thermal stress, since hardness is typically accompanied by brittleness leading to crack formation and propagation. Toughness, the combination of hardness and ductility, is required to avoid brittle fracture. Here, the authors demonstrate a strategy for simultaneously enhancing both hardness and ductility of ZrB2-rich thin films grown in pure Ar on Al2O3(0001) and Si(001) substrates at 475 degrees C. ZrB2.4 layers are deposited by dc magnetron sputtering (DCMS) from a ZrB2 target, while Zr1-xTaxBy alloy films are grown, thus varying the B/metal ratio as a function of x, by adding pulsed high-power impulse magnetron sputtering (HiPIMS) from a Ta target to deposit Zr1-xTaxBy alloy films using hybrid Ta-HiPIMS/ZrB2-DCMS sputtering with a substrate bias synchronized to the metal-rich portion of each HiPIMS pulse. The average power P-Ta (and pulse frequency) applied to the HiPIMS Ta target is varied from 0 to 1800W (0 to 300 Hz) in increments of 600W (100 Hz). The resulting boron-to-metal ratio, y = B/(Zr+Ta), in as-deposited Zr1-xTaxBy films decreases from 2.4 to 1.5 as P-Ta is increased from 0 to 1800W, while x increases from 0 to 0.3. A combination of x-ray diffraction (XRD), glancing-angle XRD, transmission electron microscopy (TEM), analytical Z-contrast scanning TEM, electron energy-loss spectroscopy, energy-dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, and atom-probe tomography reveals that all films have the hexagonal AlB2 crystal structure with a columnar nanostructure, in which the column boundaries of layers with 0 amp;lt;= x amp;lt; 0.2 are B-rich, whereas those with x amp;gt;= 0.2 are Ta-rich. The nanostructural transition, combined with changes in average column widths, results in an similar to 20% increase in hardness, from 35 to 42 GPa, with a simultaneous increase of similar to 30% in nanoindentation toughness, from 4.0 to 5.2MPa root m. Published by the AVS.

Ort, förlag, år, upplaga, sidor
A V S AMER INST PHYSICS , 2019. Vol. 37, nr 3, artikel-id 031506
Nationell ämneskategori
Oorganisk kemi
Identifikatorer
URN: urn:nbn:se:liu:diva-159001DOI: 10.1116/1.5093170ISI: 000472182400035OAI: oai:DiVA.org:liu-159001DiVA, id: diva2:1338109
Anmärkning

Funding Agencies|Swedish Research Council VR [2014-5790, 2018-03957, 642-2013-8020]; Knut and Alice Wallenbergs foundation [KAW 2015.0043]; VINNOVA [2018-04290]; Aforsk Foundation [16-359]; Carl Tryggers Stiftelse [CTS 15: 219, CTS 17: 166, CTS 14: 431]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO Mat LiU) [2009 00971]

Tillgänglig från: 2019-07-19 Skapad: 2019-07-19 Senast uppdaterad: 2019-10-28
Ingår i avhandling
1. Atom Probe Tomography of Hard Nitride and Boride Thin Films
Öppna denna publikation i ny flik eller fönster >>Atom Probe Tomography of Hard Nitride and Boride Thin Films
2019 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Hard ceramic thin films, including TiSiN, ZrAlN, ZrB2, and ZrTaB2, with applications for wear-resistant coatings, have been studied using atom probe tomography and correlated with several other analytical techniques, including X-ray diffraction, electron microscopy, and elastic recoil detection analysis. Outstanding obstacles for quantitative atom probe tomography of ceramic thin films have been surmounted.

Mass spectral overlaps in TiSiN, which make 28Si indistinguishable from 14N, was resolved by isotopic substitution with 15N, and the nanostructural distribution of elements was thus revealed in 3-D, which enabled the identification of additional structural elements within the nanostructured Ti0.81Si0.1915N film. Improvements to the growth model of TiSiN by cathodic arc deposition was suggested.

A self-organized nanolabyrinthine structure of ZrAlN, consisting of standing lamellae of fcc-ZrN and hexagonal AlN, was investigated with focus on the onset and limits of the self-organization. The local crystallographic orientational relationships were (001)ZrN || (0001)AlN and <110>ZrN || <2-1-10>AlN. Close to the MgO substrates, a smooth transition region was formed, going from segregated and disordered to the self-organized nanolabyrinthine structure. With increased growth temperature, coarse (111)-oriented ZrN grains occasionally precipitated and locally replaced the nanolabyrinthine structure. Significant local magnification effects rendered the Zr and N signals unusable, thereby inhibiting quantitative compositional analysis of the constituent phases, but the nanostructure was resolved using the Al signal.

Ceramic materials are often affected by correlated evaporation, which can result in losses due to the detector dead-time/space. A compositional correction procedure was suggested, tested against an established procedure, and applied to ZrB2. The correction was found to be less dependent on the isotope abundances and background correction compared to the established procedure. While losses due to dead-time/space occur in atom probe tomography of all materials, the correlative field evaporation behavior of ceramics significantly increases the compositional error. The evaporation behavior of ZrB2 was therefore thoroughly investigated and evidence of preferential retention, correlated evaporation, and inhomogeneous field distributions at a low-index pole was presented. The high mass resolution, relatively low multiple events percentage, and quality of the co-evaporation correlation data was partly attributed to the crystal structure and film orientation, which promoted a layer-by-layer field evaporation.

The evaporation behavior of the related ZrTaB2 films was found to be similar to that of ZrB2. The distribution of Ta in relation to Zr was investigated, showing that the column boundaries were both metal- and Ta-rich, and that there was a significant amount of Ta in solid solution within the columns.

In addition, an instrumental artefact previously not described in atom probe tomography was found in several of the materials investigated in this thesis. The artefact consists of high-density lines along the analysis direction, which cannot be related to pole artefacts. The detection system of the atom probe was identified as the cause, because the artefact patterns on detector histograms coincided with the structure of the microchannel plate. Inconsistencies in the internal boundaries of the microchannel plate multifibers from the manufacturing process can influence the signal to the detector and locally increase the detection efficiency in a pattern characteristic to the microchannel plate in question.

Altogether, this thesis shows that atom probe tomography of nitride and boride thin films is burdened by several artefacts and distortions, but that relevant material outcomes can nevertheless be achieved by informed choices of film isotopic constituents and analytical parameters, exclusion of heavily distorted regions (such as pole artefacts), and the use of compositional correction procedures when applicable.

Ort, förlag, år, upplaga, sidor
Linköping: Linköping University Electronic Press, 2019. s. 79
Serie
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1995
Nyckelord
Materials science, Atom probe tomography (APT), Ceramics, Nitrides, Borides
Nationell ämneskategori
Fysik Materialteknik Keramteknik
Identifikatorer
urn:nbn:se:liu:diva-159187 (URN)10.3384/diss.diva-159187 (DOI)9789176850435 (ISBN)
Disputation
2019-09-13, Planck, Fysikhuset, Campus Valla, Linköping, 10:15 (Engelska)
Opponent
Handledare
Tillgänglig från: 2019-08-02 Skapad: 2019-08-01 Senast uppdaterad: 2019-09-20Bibliografiskt granskad

Open Access i DiVA

fulltext(2582 kB)21 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 2582 kBChecksumma SHA-512
015a1be293dacb55218122b843429c3bf48001ab0133027fbb6981c4ec85c661ddfc2c32d25aa767baa562676a2043b69faabc58a2598e9ce826d7d09fb8e9cc
Typ fulltextMimetyp application/pdf

Övriga länkar

Förlagets fulltext

Sök vidare i DiVA

Av författaren/redaktören
Bakhit, BabakEngberg, DavidLu, JunRosén, JohannaHögberg, HansHultman, LarsPetrov, IvanGreene, Joseph EGreczynski, Grzegorz
Av organisationen
TunnfilmsfysikTekniska fakulteten
I samma tidskrift
Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films
Oorganisk kemi

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 21 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 106 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf