Transcript Clean Dry-Coating Technology for ID Chrome Replacement

Clean Dry-Coating Technology
for ID Chrome Replacement
SERDP Project # 1151
HCAT Program Review
Long Beach
April 2001
Keith Legg 847-680-9420
Technical approach - Team structure
ID Chrome Replacement
Program management: Naval Research Lab, Bruce Sartwell
Technical: Rowan Technology Group, Keith Legg
Technology development team
NRC
Technology evaluation team
Boeing, St Louis
Materials evaluation team
NRL
Nano-agglomerates
Sulzer Metco
OEM fit
Boeing, Messier-Dowty, Menasco, PEWG
Microstructure, hardness
NRL, NRC
Small particle spray, T400 comparison
Praxair
Depot fit
NADEPs-JAX & CP, CCAD, OO-ALC, ANAD
Porosity, wear
Metcut
Miniature ID gun
TAFA
Cost evaluation
CTC, BFG
Abrasion, corrosion
NRL
Fatigue, stress
Metcut
Hydraulic testing
Anniston Army Depot, Green Tweed
Keith Legg 847-680-9420
Technical objective

To demonstrate proof-of-principle for the plasma spray method for
internal diameter (ID) and non-line-of-sight surfaces:
 Improve ability to spray in constricted areas; miniature gun and
process modifications
 Understand limits, improve coating performance and reliability
 Improve underlying science and technology of plasma spray
 Improve coating properties by use of small and nano-agglomerate
particles
 Feed results into follow-on dem/val as soon as possible for use in
new weapons platforms (e.g. JSF) and maintenance of existing
systems
Keith Legg 847-680-9420
Technical Approach - Summary of
Technology Development approach
Praxair-TAFA
Praxair
Indianapolis
Sulzer Metco
NRC
All guns
Equipment
Sulzer Metco F-100
Characterize performance
– velocity and temperature
profiles
20 kW 4” ID
Praxair 2700 miniature
30kW, 1.5” ID
Sulzer Metco F-210
12kW, 2.5” ID
Powder
Standard WC-Co
Tribaloy 400
Standard WC-Co powders
All powders
Small particles
WC-Co small
particles
Nano-agglomerate WC-Co
Optimize spray conditions
Do small
particles
provide better
quality?
Best conditions for large parts
– landing gear outer cylinders
Characterize coatings and
coated tubes
Do nanoparticles give better
particles? – OSH issues
Evaluate OSH issues of
nanopowders
Nano-agglomerates
Issues
How small a diameter can
we coat?
And with what type of
powder?
Consider other materials
Keith Legg 847-680-9420
ID coating alternative materials

Why WC-Co?




Becoming used on
production landing gear and
hydraulics
Cr replacement of choice for
landing gear cylinders, axles
Much better wear resistance
than Cr
Fairly easy to spray

Why T-400?





Widely used in GTEs
Becoming used on more test
and production non-engine
parts, e.g. hydraulics
On hydraulic rods - not as
wear-resistant as WC-Co,
but better than Cr (Green,
Tweed tests)
Lubricious - can use on both
outer cylinder ID and piston
Can be made with low
porosity
Keith Legg 847-680-9420
WC-Co optimization


Wear resistance of WC-Co >> Cr
Primary concern is porosity (would like <~2%)





Leak-by, especially in 3,000 psi gas-over fluid landing gear
Likely to have poor corrosion resistance
More difficult to grind and finish smoothly
Requires polymer sealer - vacuum impregnated - extra step
Depends on
 particle size and type (how made)
 chemistry of the binder (Co alone or with additions)


temperature and velocity of particles from gun
It is worth giving up some hardness for lower porosity, higher
toughness, ease of spraying
Keith Legg 847-680-9420
Gun characterization (NRC)
Effect of H2
Flow Rate
F-100 gun
3000
140
2800
130
2005NS-F-100
Ar:85slpm
He10slpm
350A
1.25 in.
2600
2400
120
Particle Velocity (m/s)
150
3200
Particle Temperature (°C)
H2 allows up
to 50%
increase in
particle
velocity
160
T(°C)
V (m/s)
3400
110
2200
2000
100
0
0.5
1
1.5
2
2.5
Hydrogen content %
Keith Legg 847-680-9420
Operating Range F-100 gun independent control of particle T and V
H2 allows up to
50% increase in
particle velocity
He allows a decrease in
particle temperature for
the same velocity
SOD 2.5 in.
Keith Legg 847-680-9420
Effect of Ar and He flow - F-100 gun
S e c o n d a ry F lo w V s . P o ro s ity F -1 0 0 2 0 0 5 N S
2 5 .0 %
Optimum operating
ranges found for Ar,
He, H2
P orosity
2 0 .0 %
1 5 .0 %
1 0 .0 %
Increased He
5 .0 %
P rim a ry F lo w V s . P o ro s ity F -1 0 0 2 0 0 5 N S
0 .0 %
3 0 .0 %
0
25
50
100
125
150
175
200
S e c o n d a ry F lo w (L itre s /M in .)
2 5 .0 %
No matter what you do with
the most common powders,
you cannot get porosity
below 7-10%
WOULD REQUIRE SEALERS
CAN WE GET IT BETTER?
Increased Ar
2 0 .0 %
P o ro sity [% ]
75
1 5 .0 %
1 0 .0 %
5 .0 %
0 .0 %
40
50
60
70
P rim a ry F lo w (litre s /m in )
80
90
100
Keith Legg 847-680-9420
Typical microstructures
F-100 gun
19.9% porosity
Ar(85) He(10) condition
8.3% porosity
Ar(85) He(10) H2 (0.5)
condition
Keith Legg 847-680-9420
WC-Co optimization (Sulzer Metco)
Powder
Number
D 2006
D 2005NS
M 73F
SM 5843
SM 5847
D 2002
Chemical Composition
D 2003
SM 5810
A 9830
WC-17Co
WC-17Co
WC-17Co
WC 10Co 4Cr
WC 10Co 4Cr
(WC 12Co) 33Ni 9Cr 3.5Fe
2Si 2B 0.5C self-fluxing
WC 12Co 25(Ni base super
alloy)
(WC 12Co) 33Ni 9Cr 3.5Fe
2Si 2B 0.5C
(WC 12Co) 33Ni 9Cr 3.5Fe
2Si 2B 0.5C
W2C/WC 12Co
WC 12Co
WC 17Co
D 5848
D 5826
WC 10Co 4Cr
WC 17Co
SM 5803
M 439NS
M 439NS-2
Particle size
range
-30 +5.5 m
-53 +11 m
-53 +11 m
-45 +11 m
-53 +11 m
-45 +11 m
Manufacturing method
-45 +11 m
Blend
-63 +15 m
Blend
-90 +15 m
Blend
-45 +5.5 m
-63 +11 m
-53 +20 m
Fused
Spherical Composite
Spherical, Agglomerated
and densified
Spray dried and Sintered
Spray dried and Sintered
-45 +11 m
-45 +11 m
Spray died and sintered
Spray died and sintered
Spray died and sintered
Sintered and crushed
Agglomerated/Sintered
Blend
Keith Legg 847-680-9420
Diamalloy 2003
Fused WC-12Co



F-100 gun, with He and H2
Inside 3” ID tube
Porosity 4.2%


Microhardness 779 HV300

Cross section, 200X

close to requirements, may
need sealing
higher than D 2002, lower
than standard powders
May be more brittle than WC17Co
Keith Legg 847-680-9420
Diamalloy 2002
WC-12Co self-fluxing with NiCrFeSiB



F-100 gun, with He and H2
Inside 3” ID tube
Porosity <1%


Microhardness 670 HV300


very low (good)
low but acceptable
Areas of flux alloy may give
uneven wear (roughness)
Cross section, 200X
Keith Legg 847-680-9420
Tribaloy 400 optimization (Praxair)

Aiming for small powders



faster heating, greater
acceleration (coating in
smaller diameters)
lower porosity, smoother
surfaces
Initial testing



done in 3” IDs
very high porosity for nonoptimized material
very low porosity once
optimized
Keith Legg 847-680-9420
T 400 optimized
Co-109-8, Lot
#1
2” Stand Off
1/8” Advance
Data Book
No.#
S/Speed
F/Rate
Amps
Porosity
Hardness
Hv.3
Rough
ness
Ra in.
Almen
5074~8~1
1200
10
550
2%
354
202
N/A
5074~8~2
1200
20
550
1.50%
425
215
N/A
5074~12~1
2400
38
550
1.75%
413
232
+.0010
5074~12~2
2400
20
550
1.75%
399
246
.0000
5074~12~3
2400+1/4
Adv.
20
550
<.75%
394
250
.0000
5074~12~4
2400
20
450
<.5%
366
206
.0000
5074~12~6
2400
20
450
1.75%
360
249
.0000
5074~12~6
4800
20
550
<.5%
365
253
+.0020
5074~13~2
4800
20
450
<.75%
384
206
+.0060
One of the best sets of conditions - optimized
Keith Legg 847-680-9420
T 400 microstructure

Porosity <0.5%


Hardness 366 HV



Vickers indent

soft (T 400 typically 350-425)
but lubricity appears to help
Almen = 0 (no residual
stress)

Sample 5074-12-4
very low (good)
very important for fatigue
Note - alloy, so no particles
Keith Legg 847-680-9420
Process Development Team meeting
NRL, Jan 2001


Progress summarized at NRC, Sulzer, Praxair and
discussed - coatings already being done in 3” IDs
Coatings to be optimized and tested, based on data



Praxair
Tribaloy 400
Diamalloy 2003, or equivalent, fused and crushed WC-Co
Diamalloy 2002, or similar, 75(WC-Co) Ni-based self fluxing
material
Sulzer-Metco

Standard sample jig to be designed and used by all

Porosity measurements to be normalized and all final
measurements to be made at NRC

All Praxair coatings now using miniature 2700 gun
Keith Legg 847-680-9420
Interactions between ID teams






Common posting of reports and documents on HCAT site
Periodic telephone calls to bring each other up to date
KOL visited Roger Johnson to discuss ESD
KOL visited Integran to discuss electroplating
Technology analysis of ESD, brush plating, and contained-ID
plating for field repair of Cr and Cd alternatives for JSF
Joint meeting April 24 in conjunction with HCAT meeting - to
inform and get comment/guidance from users
Keith Legg 847-680-9420
Summary


Coatings can be put down in 3” IDs (open ended) with little
unmelted particle incorporation
 much better than feared - blind holes more difficult
Build-up is rapid - typically 0.003” in 20-30 min over 3” ID x 24”
long




important for cost and turnaround
Coatings can be made with low enough porosity to avoid need
for sealers (<2%)
 important for minimum leak-by and good surface finish
Most coatings have tensile stress (normal for plasma spray), but
some can be made with low or none
 important for fatigue
Coatings are softer than HVOF, but likely to be at least as wear
resistant as EHC
Keith Legg 847-680-9420