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Visualising microstructural dynamics of titanium aluminium nitride coatings under variable-temperature oxidation

Makgae, Ofentse A. LU ; Lenrick, Filip LU orcid ; Bushlya, Volodymyr LU ; Andersson, Jon M. ; M'Saoubi, Rachid LU and Ek, Martin LU orcid (2023) In Applied Surface Science 618.
Abstract

Understanding the link between titanium-aluminium nitride's (Ti1-xAlxN) physicochemical properties and structural dynamics during operation is essential to designing and fabricating advanced ceramic coatings. Here, we directly visualise the oxidation of Ti1-xAlxN (for x = 0, 0.18, 0.44, & 0.67) coatings from 100 to 1000 °C using environmental transmission electron microscopy (ETEM) imaging and energy dispersive X-ray spectroscopy (EDX) analysis. The high-frame-rate ETEM movies show that oxidation in TiN proceeds at the grain boundaries and cracks; in contrast, Ti1-xAlxN coatings transform from large as-deposited grains into oxide nanoparticles. Moreover,... (More)

Understanding the link between titanium-aluminium nitride's (Ti1-xAlxN) physicochemical properties and structural dynamics during operation is essential to designing and fabricating advanced ceramic coatings. Here, we directly visualise the oxidation of Ti1-xAlxN (for x = 0, 0.18, 0.44, & 0.67) coatings from 100 to 1000 °C using environmental transmission electron microscopy (ETEM) imaging and energy dispersive X-ray spectroscopy (EDX) analysis. The high-frame-rate ETEM movies show that oxidation in TiN proceeds at the grain boundaries and cracks; in contrast, Ti1-xAlxN coatings transform from large as-deposited grains into oxide nanoparticles. Moreover, high-resolution ETEM imaging show the presence of anatase TiO2 at the early stages of oxidation across all compositions. Above ∼ 850 °C, the oxide nanoparticles grow through crystal merging, diffusion and recrystallisation to form rutile TiO2. The EDX elemental maps coupled with secondary electron imaging reveal a uniform TiO2 sublayer decorated with increasing coverage of Al2O3 particles for x = 0.18 to 0.44. In contrast, coatings with x = 0.67 reveal a complete in-plane phase separation of Al- and Ti-oxides, which can rationalise their decreasing long-term oxidation resistance. Finally, the study provides unique insight into the real-time structural dynamics underpinning the oxidation resistance of Ti1-xAlxN coatings.

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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Coatings, Environmental TEM, In situ oxidation, Thin films, Titanium aluminium nitride
in
Applied Surface Science
volume
618
article number
156625
publisher
Elsevier
external identifiers
  • scopus:85147551635
ISSN
0169-4332
DOI
10.1016/j.apsusc.2023.156625
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2023 The Author(s)
id
7b96160a-7ebf-41d6-b113-0d830cf9134a
date added to LUP
2023-02-17 16:43:35
date last changed
2024-03-18 20:32:03
@article{7b96160a-7ebf-41d6-b113-0d830cf9134a,
  abstract     = {{<p>Understanding the link between titanium-aluminium nitride's (Ti<sub>1-x</sub>Al<sub>x</sub>N) physicochemical properties and structural dynamics during operation is essential to designing and fabricating advanced ceramic coatings. Here, we directly visualise the oxidation of Ti<sub>1-x</sub>Al<sub>x</sub>N (for x = 0, 0.18, 0.44, &amp; 0.67) coatings from 100 to 1000 °C using environmental transmission electron microscopy (ETEM) imaging and energy dispersive X-ray spectroscopy (EDX) analysis. The high-frame-rate ETEM movies show that oxidation in TiN proceeds at the grain boundaries and cracks; in contrast, Ti<sub>1-x</sub>Al<sub>x</sub>N coatings transform from large as-deposited grains into oxide nanoparticles. Moreover, high-resolution ETEM imaging show the presence of anatase TiO<sub>2</sub> at the early stages of oxidation across all compositions. Above ∼ 850 °C, the oxide nanoparticles grow through crystal merging, diffusion and recrystallisation to form rutile TiO<sub>2</sub>. The EDX elemental maps coupled with secondary electron imaging reveal a uniform TiO<sub>2</sub> sublayer decorated with increasing coverage of Al<sub>2</sub>O<sub>3</sub> particles for x = 0.18 to 0.44. In contrast, coatings with x = 0.67 reveal a complete in-plane phase separation of Al- and Ti-oxides, which can rationalise their decreasing long-term oxidation resistance. Finally, the study provides unique insight into the real-time structural dynamics underpinning the oxidation resistance of Ti<sub>1-x</sub>Al<sub>x</sub>N coatings.</p>}},
  author       = {{Makgae, Ofentse A. and Lenrick, Filip and Bushlya, Volodymyr and Andersson, Jon M. and M'Saoubi, Rachid and Ek, Martin}},
  issn         = {{0169-4332}},
  keywords     = {{Coatings; Environmental TEM; In situ oxidation; Thin films; Titanium aluminium nitride}},
  language     = {{eng}},
  month        = {{05}},
  publisher    = {{Elsevier}},
  series       = {{Applied Surface Science}},
  title        = {{Visualising microstructural dynamics of titanium aluminium nitride coatings under variable-temperature oxidation}},
  url          = {{http://dx.doi.org/10.1016/j.apsusc.2023.156625}},
  doi          = {{10.1016/j.apsusc.2023.156625}},
  volume       = {{618}},
  year         = {{2023}},
}