Zirconium carbide oxidation: Maltese Cross formation and interface characterization
File(s)
Accepted version
Published version
Author(s)
Gasparrini, C
Podor, R
Horlait, D
Chater, R
Lee, W
Type
Journal Article
Abstract
Oxidation of dense
hot pressed ZrC specimens from 10
73
–
1473 K was investigated
using an
in
-
situ
technique:
HT
-
ESEM. Cuboid specimens were monitored on the surface and on edges and corners
durin
g oxidation
in order to understand the influence of crack formation and propagation
on
the Maltese c
ross shape
development
of
the oxide
. The
oxidation
mechanism
comprised
three steps:
(1)
delamination
of sample edges
,
(2)
crack formation at
corners
and (3)
crack
propagation
towards the inner core
and formation of microcracks parallel to the interface
that
increase the
accessible
surface area
followed by
a drastic volume expansion
.
The m
icrocrack
pattern is found to be
repetitive as if a cyclic
deb
on
ding of the interface
occurred
. Characterization
of the interface by TEM and HRTEM
revealed the
interface between ZrC and ZrO
2
to
comprise
a
2
μm thick amorphous
carbon
matrix with
ZrO
2
nanocrystals embedded in it.
hot pressed ZrC specimens from 10
73
–
1473 K was investigated
using an
in
-
situ
technique:
HT
-
ESEM. Cuboid specimens were monitored on the surface and on edges and corners
durin
g oxidation
in order to understand the influence of crack formation and propagation
on
the Maltese c
ross shape
development
of
the oxide
. The
oxidation
mechanism
comprised
three steps:
(1)
delamination
of sample edges
,
(2)
crack formation at
corners
and (3)
crack
propagation
towards the inner core
and formation of microcracks parallel to the interface
that
increase the
accessible
surface area
followed by
a drastic volume expansion
.
The m
icrocrack
pattern is found to be
repetitive as if a cyclic
deb
on
ding of the interface
occurred
. Characterization
of the interface by TEM and HRTEM
revealed the
interface between ZrC and ZrO
2
to
comprise
a
2
μm thick amorphous
carbon
matrix with
ZrO
2
nanocrystals embedded in it.
Date Issued
2016-12-02
Date Acceptance
2016-07-21
Citation
Oxidation of Metals, 2016, 88 (3-4), pp.509-519
ISSN
1573-4889
Publisher
Springer Verlag (Germany)
Start Page
509
End Page
519
Journal / Book Title
Oxidation of Metals
Volume
88
Issue
3-4
Copyright Statement
© The Author(s) 2016. This article is published with open access at Springerlink.com
License URL
Sponsor
Engineering & Physical Science Research Council (E
Engineering & Physical Science Research Council (EPSRC)
Grant Number
EP/L014041/1
EP/M018563/1
Subjects
0914 Resources Engineering And Extractive Metallurgy
Materials
Publication Status
Published