Plasma spray ID coatings
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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
All coatings made in 3” ID
tubes
3 guns used
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
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
Tribaloy 400
Diamalloy 2003, or equivalent, fused and crushed WCCo
softer, lubricious, low porosity
lowest WC-Co porosity
evaluate standard and small particles
Diamalloy 2002, or similar, 75(WC-12Co) NiCrFeSiBC
self -fluxing blend
softer than WC-Co but low porosity
evaluate alloy modifications
Keith Legg 847-680-9420
Tribaloy development - Praxair, NRC
Velocity (°C)
Operational range SG-2700 mini gun
215
195
175
155
135
T-800
115
95
75
55
2000
2200
T-400 fine
2005 NS
Small particles allow higher
T, probably also higher V
But small particles (600
mesh, 20 µm) too difficult to
feed reliably
2400
2600
2800
3000
3200
3400
Temperature (°C)
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
Porosity 6%
measurement depends on met prep
best porosity method appears to be
vacuum infiltration
Hardness ~350 - 400 HV
softer than carbides
lubricious - can be used against
itself (piston + ID)
becoming used in some actuators
Almen can = 0 (no residual stress)
very important for fatigue
most plasma spray coatings are
tensile
Keith Legg 847-680-9420
Diamalloy 2003
Fused WC-12Co
Porosity 4%
Microhardness 780 HV300
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
may not matter too much in
IDs
Keith Legg 847-680-9420
Diamalloy 2002
WC-12Co self-fluxing with NiCrFeSiB
Porosity <1%
Microhardness 670 HV300
Expected to be more
lubricious and less brittle than
WC-Co
Cross section, 200X
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
Coat coupons for
all tests under ID
conditions
metallography
adhesion
wear
corrosion
fatigue
Keith Legg 847-680-9420
To be done
Standard coupon jig being
made for NRC, Sulzer Metco,
Praxair
Optimize coating parameters
to ensure samples produced
under equivalent conditions
spray coupons for testing
(fatigue, corrosion, etc)
Perfect methods for
temperature and particle
control
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
determines range of
applications
Keith Legg 847-680-9420