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