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Keith Legg 847-680-9420
Clean Dry-Coating Technologyfor ID Chrome ReplacementSERDP Project # 1151
HCAT Program ReviewLong Beach
April 2001
Keith Legg 847-680-9420
N a n o -a g g lo m e ra tesS u lze r M e tco
S m a ll p a rt ic le sp ra y, T 4 0 0 com p a risonP ra xa ir
M in ia tu re ID g unT A F A
T e ch no lo g y d e ve lo p m en t te amN R C
O E M fitB o e in g , M e ss ie r-D o w ty , M e n a sco , P E W G
D e p o t f itN A D E P s-JA X & C P , C C A D , O O -A L C , A N A D
C o s t e va lu a tionC T C , B F G
T e ch n o lo g y eva lu a tio n te amB o e ing , S t L o u is
M ic ro s tru c tu re , h a rd n e ssN R L , N R C
P o ro s ity , w e arM e tcu t
A b ra s io n , co rro s ionN R L
F a tig u e , s tre ssM e tcu t
H yd ra u lic te s tingA n n is to n A rm y D ep o t, G ree n T w e ed
M a te ria ls e va lu a tion te amN R L
ID C h ro m e R e p lace m e ntP ro g ra m m a n ag e m e n t: N a va l R e se a rch L a b , B ru ce S a rtw e ll
T e ch n ica l: R o w a n Te ch n o lo gy G ro u p , K e ith L e gg
Technical approach - Team structure
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
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)
2000
2200
2400
2600
2800
3000
3200
3400
0 0.5 1 1.5 2 2.5
Hydrogen content %
Pa
rtic
le T
em
pe
ratu
re (
°C)
100
110
120
130
140
150
160
Pa
rtic
le V
elo
cit
y (
m/s
)
T(°C)
V (m/s)
2005NS-F-100Ar:85slpmHe10slpm350A1.25 in.
H2 allows up to 50%
increase in particle velocity
Effect of H2 Flow Rate F-100 gun
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 velocitySOD 2.5 in.
65
75
85
95
105
115
125
135
145
155
2000 2500 3000 3500
Temperature (°C)
Ve
loc
ity
(m/s
)
Diamalloy 2005 w ith Ar He H2 at 1.25in.Diamalloy 2005 w ith Ar He at 1.25in.
65
75
85
95105
115
125
135
145
155
2000 2200 2400 2600 2800 3000 3200 3400
Temperature (°C)
Ve
loci
ty (
m/s
)
Amdry 983Diamalloy 2005Diamalloy 2006Diamalloy 2005 w ith He
Keith Legg 847-680-9420
Effect of Ar and He flow - F-100 gun
Primary Flow Vs. Porosity F-100 2005NS
0.0%
5.0%
10.0%
15.0%
20.0%
25.0%
30.0%
40 50 60 70 80 90 100
Primary Flow (litres/min)
Po
ros
ity
[%
]
Optimum operating ranges found for Ar,
He, H2
No matter what you do with the most common powders,
you cannot get porosity below 7-10%
WOULD REQUIRE SEALERSCAN WE GET IT BETTER?
Secondary Flow Vs. Porosity F-100 2005NS
0.0%
5.0%
10.0%
15.0%
20.0%
25.0%
0 25 50 75 100 125 150 175 200
Secondary Flow (Litres/Min.)
Po
ros
ity
Increased Ar
Increased He
Keith Legg 847-680-9420
Typical microstructuresF-100 gun
19.9% porosityAr(85) He(10) condition
8.3% porosityAr(85) He(10) H2 (0.5)
condition
Keith Legg 847-680-9420
WC-Co optimization (Sulzer Metco)
Powder Number
Chemical Composition Particle size range
Manufacturing method
D 2006 WC-17Co -30 +5.5 m Spray died and sintered D 2005NS WC-17Co -53 +11 m Spray died and sintered
M 73F WC-17Co -53 +11 m Spray died and sintered SM 5843 WC 10Co 4Cr -45 +11 m Sintered and crushed SM 5847 WC 10Co 4Cr -53 +11 m Agglomerated/Sintered D 2002 (WC 12Co) 33Ni 9Cr 3.5Fe
2Si 2B 0.5C self-fluxing -45 +11 m Blend
SM 5803 WC 12Co 25(Ni base super alloy)
-45 +11 m Blend
M 439NS (WC 12Co) 33Ni 9Cr 3.5Fe 2Si 2B 0.5C
-63 +15 m Blend
M 439NS-2 (WC 12Co) 33Ni 9Cr 3.5Fe 2Si 2B 0.5C
-90 +15 m Blend
D 2003 W2C/WC 12Co -45 +5.5 m Fused SM 5810 WC 12Co -63 +11 m Spherical Composite A 9830 WC 17Co -53 +20 m Spherical, Agglomerated
and densified D 5848 WC 10Co 4Cr -45 +11 m Spray dried and Sintered D 5826 WC 17Co -45 +11 m Spray dried and Sintered
Keith Legg 847-680-9420
Diamalloy 2003 Fused WC-12Co
F-100 gun, with He and H2
Inside 3” ID tube Porosity 4.2%
close to requirements, may need sealing
Microhardness 779 HV300
higher than D 2002, lower than standard powders
May be more brittle than WC-17Co
Cross section, 200X
Keith Legg 847-680-9420
Diamalloy 2002WC-12Co self-fluxing with NiCrFeSiB
F-100 gun, with He and H2
Inside 3” ID tube Porosity <1%
very low (good) Microhardness 670 HV300
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
non-optimized material very low porosity once
optimized
Keith Legg 847-680-9420
T 400 optimized
One of the best sets of conditions - optimized
Keith Legg 847-680-9420
T 400 microstructure
Porosity <0.5% very low (good)
Hardness 366 HV soft (T 400 typically 350-
425) but lubricity appears to
help Almen = 0 (no residual
stress) very important for
fatigue Note - alloy, so no
particles
Sample 5074-12-4 Vickers indent
Keith Legg 847-680-9420
Process Development Team meetingNRL, 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 Tribaloy 400 Diamalloy 2003, or equivalent, fused and crushed WC-Co Diamalloy 2002, or similar, 75(WC-Co) Ni-based self
fluxing material
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
Praxair
Sulzer-Metco
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
Recommended