Accelerated oxidation behavior of NbSi2 coating grown on Nb substrate at 600–900 °C

•Study of accelerated isothermal oxidation behavior of NbSi2 coating grown on Nb substrate in air at 600–900 °C.•Pesting-induced accelerated oxidation was due to the cracking and spalling of NbSi2 coating at 700 °C.•Oxide fracture-induced accelerated oxidation was due to the cracking of oxide scale...

Full description

Saved in:
Bibliographic Details
Published inCorrosion science Vol. 141; pp. 97 - 108
Main Authors Yoon, Jin-Kook, Kim, Gyeung-Ho
Format Journal Article
LanguageEnglish
Published Amsterdam Elsevier Ltd 15.08.2018
Elsevier BV
Subjects
A. Intermallics
Alloys
B. SEM
B. TEM
B. XRD
C. Oxidation
Coating
Composite materials
Metal oxides
Oxidation
Pesting (intermetallics)
Stress relaxation
Substrates
A. Intermallics
B. SEM
B. XRD
C. Oxidation
B. TEM
Online AccessGet full text

Cover

More Information
Summary:•Study of accelerated isothermal oxidation behavior of NbSi2 coating grown on Nb substrate in air at 600–900 °C.•Pesting-induced accelerated oxidation was due to the cracking and spalling of NbSi2 coating at 700 °C.•Oxide fracture-induced accelerated oxidation was due to the cracking of oxide scale at 750 °C.•Accelerated oxidation model of NbSi2 coating has been established. Isothermal oxidation of NbSi2 coating formed on Nb substrate was investigated in air at 600–900 °C, which exhibited the complex and accelerated kinetics at intermediate temperatures and failed due to either the cracking of the NbSi2 coating or the oxide layer formed. This complex oxidation behavior was governed by the balance between the stress generated by the forming of oxide phases and the subsequent stress relaxation processes. Pesting-induced accelerated oxidation at 700 °C was affected by extrinsic factors such as pre-existing defects in NbSi2 coating. Accelerated oxidation originated from the oxide layer cracking at 750 °C was intrinsic to NbSi2.
ISSN:0010-938X
1879-0496
DOI:10.1016/j.corsci.2018.07.001