Processing and Application of Ceramics,
Год журнала:
2023,
Номер
17(4), С. 384 - 392
Опубликована: Янв. 1, 2023
The
development
of
high-speed
aerial
vehicles
urgently
requires
high-performance
integrated
materials
for
ablation
resistance,
thermal
insulation
and
oxidant
protection
under
high
temperature.
previously
prepared
carbon
aerogel
composites
(C/CA),
with
ultra-high
temperature
properties,
were
impregnated
SiCO
precursor
sol
pyrolysed
in
nitrogen
atmosphere
at
1200?C.
impregnation/pyrolysis
process
was
performed
once,
twice
thrice
to
obtain
three
different
C/C-SiCO
nanoporous
ceramic
composites.
Further,
TaSi2-MoSi2-borosilicate
glass
(TM-BG)
coating
or
TaSi2-MoSi2-ZrB2-borosilicate
(TMZBG)
on
the
surface
through
slurry
brushing
combined
graphite
powder
embedded
sintering
process.
By
simulating
actual
application
environment
oxygen
acetylene
flame
test,
resistance
samples
studied
their
oxidation
mechanism
analysed.
results
show
that
rate
after
200
s
1600
?C
decreases
increase
number
steps
modified
significantly
enhanced.
addition
ZrB2
improves
compatibility
between
substrates
coating,
TMZ-BG
coated
sample
has
better
resistance.
At
temperature,
borosilicate
is
a
viscous
flow
state.
Meanwhile
SiO2
generated
by
other
silicide
raw
forms
dense
layer
surface,
which
can
be
used
as
an
barrier
provide
substrates.
coating-modified
porous
are
expected
high-temperature
ablation-resistant
material
system
new
aerospace
vehicles.
ACS Applied Nano Materials,
Год журнала:
2024,
Номер
7(16), С. 19527 - 19537
Опубликована: Авг. 6, 2024
High-performance
thermal
protection
materials
are
urgently
needed
for
applications
under
extreme
conditions.
Organic
aerogels
considered
to
be
promising
and
efficient
materials,
but
their
low
mass
residuals
have
been
the
main
obstacles
limiting
development
application.
Herein,
by
an
in
situ
copolymerization
of
benzoxazine
prepolymers
N,N-dimethylformamide
(DMF)-soluble
silica
(SiO2)
precursors,
polybenzoxazine
(PBO)
with
increased
SiO2
contents
was
formed,
leading
high
residual
SiO2/PBO
(PBOS)
dual-network
nanoporous
structures.
The
structures
PBOS
were
obtained
owing
similar
gelation
cross-linking
rates
PBO
SiO2,
facilitated
introduction
ethanol
temperature.
resulting
exhibited
(75.96%
Ar,
increase
approximately
26%;
52.23%
air,
30%),
considerably
higher
than
those
existing
silicon-modified
aerogels.
PBOS-4
aerogel
demonstrated
excellent
high-temperature
insulation
properties
maintaining
a
back
temperature
59.9
°C
when
exposed
1200
butane
flame
600
s.
Benefiting
from
stability,
quartz
fiber-reinforced
(QF/PBOS-4)
composite
outstanding
ablation
resistance
1500
oxyacetylene
s,
linear
0.8
μm
s–1
0.67
mg
s–1,
respectively.
This
study
presents
method
producing
high-performance
suitable
aerospace
applications.
By
addressing
inorganic–organic
compatibility
issues
low-density
this
research
enhances
potential
use
PBO-based
composites
both
civil
military
Aerogels
are
three-dimensional
nanomaterials
with
low
thermal
conductivity,
density,
high
specific
surface
area,
and
porosity.
They
have
demonstrated
remarkable
performance
advantages
in
insulation,
catalysis,
adsorption
recent
years.
However,
their
inherent
brittleness
weak
skeletal
structure
limit
applications.
In
order
to
improve
the
resilience
expand
capabilities
of
aerogels,
it
is
essential
optimize
intrinsic
properties.
The
chemical
vapor
deposition
(CVD)
method
offers
a
number
advantages,
including
fine
control,
selectivity,
ability
modify
aerogel
both
outer
inner
layer.
This
approach
allows
for
reinforcement
gel
skeleton
while
achieving
functionalization.
paper
reviews
research
progress
modification
by
CVD
focus
on
hydrophobic
modification,
structural
improvement,
antioxidant
catalytic
etc.
light
current
demand
applications
difficulties
encountered
modifying
this
review
proposes
future
directions
CVD.
Processing and Application of Ceramics,
Год журнала:
2023,
Номер
17(4), С. 384 - 392
Опубликована: Янв. 1, 2023
The
development
of
high-speed
aerial
vehicles
urgently
requires
high-performance
integrated
materials
for
ablation
resistance,
thermal
insulation
and
oxidant
protection
under
high
temperature.
previously
prepared
carbon
aerogel
composites
(C/CA),
with
ultra-high
temperature
properties,
were
impregnated
SiCO
precursor
sol
pyrolysed
in
nitrogen
atmosphere
at
1200?C.
impregnation/pyrolysis
process
was
performed
once,
twice
thrice
to
obtain
three
different
C/C-SiCO
nanoporous
ceramic
composites.
Further,
TaSi2-MoSi2-borosilicate
glass
(TM-BG)
coating
or
TaSi2-MoSi2-ZrB2-borosilicate
(TMZBG)
on
the
surface
through
slurry
brushing
combined
graphite
powder
embedded
sintering
process.
By
simulating
actual
application
environment
oxygen
acetylene
flame
test,
resistance
samples
studied
their
oxidation
mechanism
analysed.
results
show
that
rate
after
200
s
1600
?C
decreases
increase
number
steps
modified
significantly
enhanced.
addition
ZrB2
improves
compatibility
between
substrates
coating,
TMZ-BG
coated
sample
has
better
resistance.
At
temperature,
borosilicate
is
a
viscous
flow
state.
Meanwhile
SiO2
generated
by
other
silicide
raw
forms
dense
layer
surface,
which
can
be
used
as
an
barrier
provide
substrates.
coating-modified
porous
are
expected
high-temperature
ablation-resistant
material
system
new
aerospace
vehicles.
