Transcript Plasma spray ID coatings

Plasma spray ID coatings
HCAT Program Review
August 2001
Toronto
Keith Legg 847-680-9420
Summary of technology development
approach
Praxair
Sulzer Metco
E
q
u
i
p
m Praxair 2700
e
n 30kW, 1.5” ID
t
NRC
All guns
F-100, 20 kW 4” ID
Characterize performance – velocity
and temperature profiles
F-210, 12kW, 2.5”ID
F-300, 9 kW, 1.6” ID
P Tribaloy 400
o
WC-Co small particles
w
d
e
r
I
s
s
u
e
s
How small a diameter can we coat?
Powder and temperature control
Do small particles provide better
quality?
Standard WC-Co powders
All powders
Nano-agglomerate WC-Co
Optimize spray conditions
WC-Co self-fluxing powder
Consider other materials
Best conditions for large parts – landing gear
outer cylinders
Characterize coatings and coated
tubes
Do nanoparticles give better coaitngs?
Evaluate OSH issues
Keith Legg 847-680-9420
The story so far
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All coatings made in 3” ID
tubes
3 guns used
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Praxair 2700 (1.5” min)
SM F100, F210
perhaps look at new SM
F300 miniature gun
Evaluated large number of
WC materials to find those
with lowest porosity
Designed common coupon
coating rig
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Measured particle T and V for
guns and powders so can
determine process windows
and transfer processes
Begun to develop uniform
porosity measurement
procedure
In midst of optimization
preparatory to making test
coupons
Keith Legg 847-680-9420
Materials to be optimized
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Tribaloy 400
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Diamalloy 2003, or equivalent, fused and crushed WCCo
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softer, lubricious, low porosity
lowest WC-Co porosity
evaluate standard and small particles
Diamalloy 2002, or similar, 75(WC-12Co) NiCrFeSiBC
self -fluxing blend
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softer than WC-Co but low porosity
evaluate alloy modifications
Keith Legg 847-680-9420
Tribaloy development - Praxair, NRC
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Velocity (°C)
Operational range SG-2700 mini gun
215
195
175
155
135
T-800
115
95
75
55
2000
2200
T-400 fine
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2005 NS
Small particles allow higher
T, probably also higher V
But small particles (600
mesh, 20 µm) too difficult to
feed reliably
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2400
2600
2800
3000
3200
3400
Temperature (°C)
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trials continuing with 400
mesh, 38µm powder),
which feeds much more
readily
smooth, low porosity
decent coatings at 1.5”
standoff (approx 2” ID)
with 38µm powder
Keith Legg 847-680-9420
T 400 microstructure
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Porosity 6%
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measurement depends on met prep
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best porosity method appears to be
vacuum infiltration
Hardness ~350 - 400 HV
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softer than carbides
lubricious - can be used against
itself (piston + ID)
becoming used in some actuators
Almen can = 0 (no residual stress)
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very important for fatigue
most plasma spray coatings are
tensile
Keith Legg 847-680-9420
Diamalloy 2003
Fused WC-12Co
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Porosity 4%
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Microhardness 780 HV300
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Cross section, 200X
close to requirements, may
need sealing
lower than standard OD
coatings, but certainly
adequate
Likely to be more brittle than
WC-17Co
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may not matter too much in
IDs
Keith Legg 847-680-9420
Diamalloy 2002
WC-12Co self-fluxing with NiCrFeSiB
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Porosity <1%
Microhardness 670 HV300
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Expected to be more
lubricious and less brittle than
WC-Co
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Cross section, 200X
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lower than WC-12Co but
acceptable
may be ideal combination of
wear resistance, lubricity,
porosity, toughness
blend - can adjust blend for
optimum combination of
wear and lubricity
May be good for ODs too
Keith Legg 847-680-9420
Sample holder - 3”ID
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Coat coupons for
all tests under ID
conditions
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metallography
adhesion
wear
corrosion
fatigue
Keith Legg 847-680-9420
To be done
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Standard coupon jig being
made for NRC, Sulzer Metco,
Praxair
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Optimize coating parameters
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to ensure samples produced
under equivalent conditions
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spray coupons for testing
(fatigue, corrosion, etc)
Perfect methods for
temperature and particle
control
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Porosity measurements to be
normalized and all final
measurements to be made at
NRC
S-M may evaluate new F-300
miniature gun
Determine minimum
sprayable ID
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determines range of
applications
Keith Legg 847-680-9420