Surface oxidation of nanocrystalline CVD TiB2 hard coatings revealed by cross-sectional nano-analytics and in-situ micro-cantilever testing

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F20%3APU140148" target="_blank" >RIV/00216305:26620/20:PU140148 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1016/j.surfcoat.2020.126181" target="_blank" >https://doi.org/10.1016/j.surfcoat.2020.126181</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.surfcoat.2020.126181" target="_blank" >10.1016/j.surfcoat.2020.126181</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Surface oxidation of nanocrystalline CVD TiB2 hard coatings revealed by cross-sectional nano-analytics and in-situ micro-cantilever testing

Popis výsledku v původním jazyce

Nanocrystalline TiB2 coatings grown by chemical vapour deposition (CVD) are employed e.g. as hard protective coatings on cemented carbide cutting tools, owing to their high wear resistance, hardness and melting point, as well as superior thermal stability. This work applied novel cross-sectional nano-analytical techniques to investigate the effects of prolonged surface oxidation of a CVD bi-layer coating of similar to 3.4 mu m thickness, consisting of a nanocrystalline TiB2 protective top layer and a TiN diffusion-barrier bottom layer. Synchrotron X-ray diffraction with a nano-focussed 70 nm beam revealed cross-sectional phase compositions and residual stress gradients in the coating in as-deposited and oxidised states. Transmission electron microscopy showed a clear oxidation front, the existence of a similar to 400 nm thick zone of coexistence of TiB2 and rutile TiO2, which coincided with a marked decrease in compressive residual stress, as well as an overlying morphologically stratified TiO2 layer. In-situ micro-cantilever experiments confirmed the structural integrity of the TiB2 phase below the coexistence zone, where no significant oxidation-induced change in fracture stress was detected, while Young's modulus decreased by similar to 25%. In conclusion, the pursued nano-analytics approach revealed detailed cross-sectional correlations between oxidation-related coating disintegration, microstructure, residual stresses and mechanical properties.

Název v anglickém jazyce

Surface oxidation of nanocrystalline CVD TiB2 hard coatings revealed by cross-sectional nano-analytics and in-situ micro-cantilever testing

Popis výsledku anglicky

Nanocrystalline TiB2 coatings grown by chemical vapour deposition (CVD) are employed e.g. as hard protective coatings on cemented carbide cutting tools, owing to their high wear resistance, hardness and melting point, as well as superior thermal stability. This work applied novel cross-sectional nano-analytical techniques to investigate the effects of prolonged surface oxidation of a CVD bi-layer coating of similar to 3.4 mu m thickness, consisting of a nanocrystalline TiB2 protective top layer and a TiN diffusion-barrier bottom layer. Synchrotron X-ray diffraction with a nano-focussed 70 nm beam revealed cross-sectional phase compositions and residual stress gradients in the coating in as-deposited and oxidised states. Transmission electron microscopy showed a clear oxidation front, the existence of a similar to 400 nm thick zone of coexistence of TiB2 and rutile TiO2, which coincided with a marked decrease in compressive residual stress, as well as an overlying morphologically stratified TiO2 layer. In-situ micro-cantilever experiments confirmed the structural integrity of the TiB2 phase below the coexistence zone, where no significant oxidation-induced change in fracture stress was detected, while Young's modulus decreased by similar to 25%. In conclusion, the pursued nano-analytics approach revealed detailed cross-sectional correlations between oxidation-related coating disintegration, microstructure, residual stresses and mechanical properties.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20506 - Coating and films

Projekt

—

Návaznosti

—

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Surface and Coatings Technology

ISSN

0257-8972

e-ISSN

—

Svazek periodika

399

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

9

Strana od-do

„126181-1“-„126181-9“

Kód UT WoS článku

000563807700067

EID výsledku v databázi Scopus

—