Keith Legg 847-680-9420

Test Status Overview

HCAT Program ReviewNASA, Florida

Dec 13,14, 2000

Keith Legg 847-680-9420

Rationale

A lot of data has been generated in HCAT/CHCAT program in the past 3 or 4 months

Aim is to show overall status - where we are in testing and what we have learned overall Put current data in a logical order Address what we are doing to resolve some testing

issues Suggest some “compartments” for existing and new

data

Keith Legg 847-680-9420

Overview

Aircraft use of HVOF coatings

Why are we doing this? - commercial flight tests

Overall status of JTP tests JTP - Corrosion, wear,

fatigue, embrittlement, impact

Ancillary - Process specs, producibility, additional corrosion, additional fatigue, failure mechanisms

Conditions seen by real parts

Summary of findings to date

What does all this mean for actual usage?

Where does it work just fine?

Where do we need to worry?

Keith Legg 847-680-9420

Flight testing - Why are we doing this?

Flight testing (Boeing, Delta, Lufthansa etc.) shows acceptable performance with no serious problems Wear performance much better than chrome

no gouges, striations, flaking, etc. commonly seen in Cr better seal life if Ra~4” (rapid seal damage if rough) some FPI crack pattern indications on Lufthansa aft inner

cylinders (Barkhausen showed no crack penetration to substrate), nothing requiring removal from service

Typical chrome damage - axle

Keith Legg 847-680-9420

Production use of HVOF WC-Co and WC-CoCr coatings

Keith Legg 847-680-9420

Production use of HVOF WC-Co and WC-CoCr coatings (cont.)

Qualified for landing gear repair <0.010”

Keith Legg 847-680-9420

Production use of HVOF landing gear coatings - Messier-Dowty

Note production use on high performance aircraft

Program-p/n Part name Type of coating Area Remarks

F/A-18 E/F 74A430702 74A430616

Piston head assy Retract Actuator NLG Cover assy Gear/manifold

Diamalloy 1004 (Al bronze) Applied per AMS2447 Tribaloy T400

6.612 OD 8.974 ID

Production part Production part

F/A-18 C/D 74A410603 Head, Piston Shock Absorber

MLGF-18 E/F

Diamalloy 1004 (Al bronze) Applied per AMS2447

OD R&O DRED

Hawker 4000 34520-1 Lock link outboard forward

door mechanism NLG WC-Co per DCMP 210 (AMS2447-7)

Flat stops Production part

REO 450626-01

Tube Restrictor Support AMS 2447-4 Ni95-Al5

2.623/2.621 OD R&O

74A410509 Axle of the polygon AMS 2447-9 2.931/3.374 polygon

In progress

Cl601RJ 17114-1

Shock strut piston MLG WC-Co-Cr per DCMP 213 (AMS 2447-9)

4.614 OD Under evaluation in service by Air Canada, NIEO

17207-1

Shock strut pin MLG

WC-Co-Cr per DCMP 213 (AMS 2447-9)

1.498 OD Under evaluation in service by Air Canada, NIEO

A340 CLG 37173-101 37174-101 15173-101 15174-101

Sleeve thrust shock strut Tribaloy T400 DCMP 203 (AMS2447-2)

2.348 ID Production part

BD 100 40672 Pin, Piston Tube

NLG WC-Co-Cr per DCMP 213 (AMS 2447-9)

0.866 OD Production part

Keith Legg 847-680-9420

Data summary:Landing Gear JTP - Coupon test data

Data Item Test 25 50 75 100 Pass Fail NotesCorrosion

C-HCAT salt fog ASTM B-117 x Standard flatUS-HCAT salt fog B117 ??? Modified sample. Retesting

US-HCAT cyclic salt fog GM 9540P/B ??? Modified sample. RetestingH Embrittlement

US-HCAT Deposition ASTM F-519 x No embrittlement by HVOFUS-HCAT H Evolution ASTM F-519 - - No acceptance criteria

US-HCAT Environmental Emb. ASTM F-519Fatigue WC-Co (Hourglass)

US-HCAT in air 0.003" ASTM E-466 x R=-1, 0.1US-HCAT in air 0.010" ASTM E-466 x R=-1, 0.1

US-HCAT corrosion ASTM E-466 x R=-1, 0.1Fatigue WC-CoCr (Smooth bar)

C-HCAT air 0.003" thick ASTM E-466 x R=-1. Delamination above 180 ksi loadC-HCAT air 0.010" thick ASTM E-466 ??? R=-1. Delamination above 125 ksi load

C-HCAT corrosion ASTM E-466 ??? R=-1. Rapid corrosion initial testsC-HCAT low temp. ASTM E-466

ImpactDropped ball Data being obtained

Gravelometry ASTM D-3170 x Equivalent or better than CrWear

Fretting GEAE Data complete - being analyzedOsc. piston/bushing Hydraulic simul. Data complete - being analyzed

Completeness

Keith Legg 847-680-9420

Data summary:Propeller Hub JTP - Coupon test data

Data Item Test 25 50 75 100 Pass Fail NotesCorrosion

WC-Co, WC-CoCr, T800, Ni plate ASTM B-117 Standard 4"x6" flat panelFatigue (Hourglass)

WC-Co, T800, Cr ASTM E-466 HSD hourglass, R=0.1WC-Co, T800 ASTM E-466 HSD notched hourglass, R=0.1

WearLarge stroke and dither HSD HSD wear plates

Toxicity leachingWC-CoCr, T400, T800 waste EPA 1311 Acetic acid leach

Completeness

Keith Legg 847-680-9420

Corrosion

C-HCAT B117 JTP work complete

HVOF performed significantly better than chrome - Pass

US-HCAT B117 Initial test results reported in

Ottawa, Aug 00 HVOF coatings worse than

Cr - Fail Appears to be a testing issue

Outstanding issues - resolution of US-HCAT results

Retesting under way Different sealing - Boeing Cd method 2 different geometries (Flats and cylinders) 2 different deposition conditions (Southwest Aero,

Hitemco) 2 different cabinets

Keith Legg 847-680-9420

Embrittlement

Tests partially complete Sequence 1 - HVOF does not cause embrittlement -

Pass Sequence 2 - Not yet complete

H2 can diffuse through HVOF coating May need longer bake

Sequence 3 begun - no data yet Outstanding issues

Environmental embrittlement measurements in process

Coating may lower Kt - calculations and tests under way at Heroux

Keith Legg 847-680-9420

Fatigue - WC-Co

WC-Co US-HCAT testing

complete All WC-Co air fatigue

data equal to or better than Cr - Pass

All WC-Co corrosion-fatigue data equal to or better than Cr - Pass

Delamination from some specimens at high cycles

WC-CoCr WC-CoCr 0.003”

delamination at high load - Pass below 180 ksi, Fail above 180 ksi

WC-CoCr 0.010” delamination at high load - Pass below 125 ksi, Fail above 125 ksi

WC-CoCr corrosion-fatigue - Fail??

Not a structural issue, but a functional issue (Messier-Dowty)

Outstanding issues Results of WC-CoCr fatigue testing

being addressed under Ancillary Testing

Keith Legg 847-680-9420

Wear

Fretting and sliding (hydraulic) Data evaluation largely complete HVOF better than or equal to Cr

Rig and flight tests all show better wear performance Less striation, wear, roughening (Delta, Greene

Tweed) Less wear and leakage of seals (Greene, Tweed)

Keith Legg 847-680-9420

Impact

Drop ball testing Under way

Gravelometry (Boeing) Completed - HVOF as good as or better than Cr - Pass

Keith Legg 847-680-9420

Data summary:Landing Gear JTP - Rig and flight testing

Data Item Test 25 50 75 100 Pass Fail NotesRig tests

Boeing F-18 LG pins Full scale x HVOF pins included in rig testHydraulic testing Hydraulic x Greene, Tweed - long stroke and dithering spectrum

M-D F-18 E/F NLG fat. Fatigue Without catapult loadsM-D F-18 E/F drag brace fat. Endurance

BFG Dash-8/400 MLG Full scale Rig complete, awaiting all test item partsBFG NLG steering act. Full scale

BFG simulated piston fat. Full scale sim Full scale piston fatigue simulationBoeing C-17 forward MLG Full scale Durability - proposed. Out for coordination

Repair scheme rig (Heroux)CF-18 A/B NLG shock strut Full scale HVOF restrictor tube - compression, cyclic loadingCF-18 A/B MLG crank assy Full scale Torsion loads equivalent to landing loads

CC-130 steering collar Full scale Endurance lifeFlight tests

Delta B737, 757, 767 LG x Internal Delta, not HCAT-sponsoredM-D CF-18 polygon repair x Internal Messier-Dowty, not HCAT-sponsored

NADEP-JAX P-3C-HCAT DND C-130 C-HCAT testing

KC-135, MLG, NLG piston Air Force - military typical worst caseF-16 NLG Air Force - high performance worst case

Completeness

Keith Legg 847-680-9420

Data summary:Propeller Hub JTP Rig and flight testing

Data Item Test 25 50 75 100 Pass Fail NotesRig tests

54H60 low pitch stop lever sleeve Piston stroke WC-Co and T800Flight tests

P-3 propeller 275 flight hrs Tail shaft hub and sleeve lever

Completeness

Keith Legg 847-680-9420

Hydraulic testing - Greene, Tweed

PTFE (Enercap) much better performance with WC

low leakage low rod wear

Elastomer rapidly damaged

not a problem with long stroke utility actuators and landing gear at 4 Ra

5

15 25 35 45

WC-Co, ACTTribaloy, ACT

Chrome, ACT

WC-Co-Cr, EnercapWC-Co, Enercap

Tribaloy, Enercap

Chrome, Enercap

0

500

1000

1500

2000

2500

Lea

kage

(g

ram

s)

Cycles (millions) 4-9 ” Ra

Keith Legg 847-680-9420

Landing gear rig tests

Boeing F/A-18 E/F landing gear pins HVOF coatings “passed” full scale rig fatigue test

darkened, but no wear damage, passed MPI

Outstanding - Additional full scale tests to be done by C-HCAT Messier-Dowty F-18 E/F NLG fatigue Messier-Dowty F-18 E/F drag brace fatigue

including catapult loads BFG Dash-8/400 MLG BFG NLG steering actuator BFG simulated piston fatigue

Keith Legg 847-680-9420

Flight tests

Delta B737, 757, 767 nose and main landing gear Inner cylinders, axles, axle sleeves

Passed - WC-CoCr qualified for O&R

Boeing 767-400 HVOF WC-CoCr flight qualified and used in production

Canadian F-18 MLG Messier-Dowty polygon repair

WC-CoCr Repair scheme approved

Outstanding - NADEP-JAX P3, DND C-130 testing

Keith Legg 847-680-9420

Data summary -Ancillary tests

Data Item Test 25 50 75 100 Pass Fail NotesProcess parameters

US-HCAT WC-Co DOE - -C-HCAT NRC WC-CoCr DOE - -

Commercial - SWA, Hitemco - - Boeing QPL processesGrinding/finishing

NADEP-JAX - - Low stress grind used on samplesDelta Airlines - - Used on flight test landing gear

HerouxStripping

NADEP-CP, S'west Aero x WC-Co and WC-CoCr strip w/RochelleCTC water jet x Incomplete stripping

HerouxR&O Fluid compatibility

HerouxNDI

HerouxDelta, Boeing flight tests - - FPI, Barkhausen good; MPI poor

CorrosionBeach exposure x Flat samples - generic tests

Salt fog B117 x Flat samples - generic testsCyclic salt fog GM 9540P/B x Flat samples - generic tests

US-HCAT comparison tests B117 New seal; flat, round, var. vendors, var. cabinetsFatigue (Smooth bar)

US/C-HCAT WC-CoCr air ASTM E-466Fracture mechanisms

C-HCAT NRC/Orenda - -Specifications

AMS specs - - Powder, grinding, coating

Completeness

Keith Legg 847-680-9420

Process parameters

WC-Co optimized by Jerry Schell by DOE methods OO-ALC, Hitemco - JP 5000, DJ Process designed for 8-12 Almen compressive stress

WC-CoCr optimized by Jean-Gabriel Legoux, NRC by DOE methods DJ-gun at NRC and VacAero Process designed for 8-12 Almen compressive stress Coating parameters different from QPL conditions

used by Southwest Aero

Keith Legg 847-680-9420

Grinding and finishing

Overall finding - for seals need 4” or less Ra Use fine grind or superfinish (specify other parameters?)

Low stress grinding developed by Jon Devereaux at NADEP-JAX used on all US-HCAT samples

Surface measurement and superfinishing developed for landing gear by Jay Randolph at Delta

Testing carried out by John Falkowski (Boeing) and Jim Nuse (Southwest Aeroservice) - AESF paper

Additional testing under way Boeing, SW Aero, Sulzer Metco, Engelhard, Praxair, Green

Tweed, Supfina, Delta

Keith Legg 847-680-9420

Stripping

Water jet does not work very well Rochelle salt works well for WC-Co and WC-

CoCr SW Aero, Sulzer Metco NADEP-Cherry Point, NTS

Testing at Praxair and others shows no embrittlement with strippers

No good method for T400 yet Outstanding - need good chemical strip for

Tribaloy

Keith Legg 847-680-9420

Fluid compatibility

Under way shortly at Heroux Will include evaluations of hydrogen

embrittlement due to fluids

Keith Legg 847-680-9420

NDI

FPI best method so far Delta, Boeing

MPI not effective Boeing has used Barkhausen with some success Heroux testing begun Outstanding - how detect cracks in substrate

without removing coating?

Keith Legg 847-680-9420

Corrosion

All HCAT generic, C-HCAT, Lufthansa data on flats shows HVOF having better performance than Cr US-HCAT Landing gear JTP data on rods showed worse

than Cr - Fail Repeating with better edge seal - comparing sample

shapes, deposition conditions, test locations

Outstanding - Resolution of poor US-HCAT test performance (under way)

Keith Legg 847-680-9420

Fatigue and fracture

Fatigue of WC-CoCr - the picture folks took back from Ottawa meeting

Keith Legg 847-680-9420

Fatigue and fracture

Findings of cracking by AFRL (Bob Ware) Careful analysis done at NRC (Jason Dyer, Peter Au)

WC-CoCr fails, cracks and delaminates under high compressive load (R=-1)

0.003” coating, failure at 180 ksi and above 0.010” coating, failure at 125 ksi and above (note that thicker

coating carries more load) cracks grow down from coating surface and often run parallel

to interface (similar mechanism to that designed into composites)

cracks do not appear to propagate from coating into substrate Surfaces of WC-CoCr fatigue specimens from Southwest

Aeroservice also show crack pattern and some spalling at failure and runout

This shows there may be operational limits of WC-CoCr

Keith Legg 847-680-9420

Where should we be testing?What are the real-world requirements?

What are the functional limits of WC-CoCr and WC-Co?

Questions:

Keith Legg 847-680-9420

Bend test of Praxair WC-CoCr. Reported by Jay Randolph, Delta

Airlines, July 1998

Fatigue and cracking - historical

Fracture data - John Quets, Shane Arthur WC-Co initially designed using bend test cracking data WC-CoCr designed to have better corrosion performance,

but lower fracture strength So, WC composite coatings balance hardness and wear

resistance against brittleness (fracture strength)

1998 - Crack-like indications found by FPI on aft side of WC-CoCr-coated Lufthansa landing gear. Barkhausen analysis by Boeing showed no crack propagation into steel. Returned to service - no reported problems.

Keith Legg 847-680-9420

Landing gear design and fatigue testing

Designers do not design to specimen test data Coupons provide stress engineers the data to start

analyzing for customer and air-worthiness justification

Difficult to translate from load on full scale item to stress on test coupon

Qualification always depends on full-scale item fatigue testing under spectrum loading to 2 or 4 lifetimes

Bulk of public domain data for AerMet 100 was run at 150 ksi or less (Roger Eybel) a few points were run higher for interest sake

Keith Legg 847-680-9420

Fatigue - Loads on Landing Gear

Name Company Maximum stress (kpsi)

R ratio Sample type Notes

Gary Erickson Boeing Commercial 170 0.1 Large hourglass Vendor qual testRoque Panza-Giosa BFG 180 -1 Al alloys 20ksiCraig Edwards GA/Air Force 180 -1 Actual LG 180kpsi is once-in-a-lifetime

event. 135 normal useRoger Eybel Messier Dowty 150 A100 test

specimensBulk of public domain data - some at higher load for interest only

Dave Weldon Messier Dowty 211 Full scale gear Drag Brace Trunnion Pin Test - max bending stress

Michael Kane NAVAIR 180 Test specimens Limit Ultimate (P3, E6, V22)Michael Kane NAVAIR 240 Test specimens Design Ultimate (high

performance)Nihad Ben-Salah Heroux 195 0.1, -1 Test specimens 4340 (90% of yield)

207 0.1, -1 Test specimens 300M (90% yield)225 0.1, -1 Test specimens A100 (90% of yield)

Keith Legg 847-680-9420

Fatigue - Loads on Landing Gear

Makes no sense to test coatings above levels used in full rig tests

Looks as though we have the following maximum needs: Commercial 170 ksi, R=0.1 Military, typical 180 ksi, R=-1 Military, high performance 240 ksi, R=-1

Questions: At what loads/cycles were F-18 landing gear qualified? Do you really go to yield thousands of times?

Keith Legg 847-680-9420

Summary of major ongoing work

Corrosion Additional tests planned

samples made

Fatigue C-HCAT testing 0.003”

WC-CoCr below 180 ksi Rethinking tests for

0.010” WC-CoCr Comparative testing with

SW Aero WC-CoCr and WC-Co

Embrittlement Environmental embritt.

Ball impact - in progress

Producibility testing Heroux - grinding,

stripping, NDI, fluids, etc. Rig testing

BFG, Messier-Dowty Flight testing

NADEP-JAX P3 DND CC-130

Keith Legg 847-680-9420

Remaining issues being resolved

US-HCAT corrosion testing to be redone obviously testing problem

Fatigue testing Not a structural issue that will cause failure, but a

functional issue that will impose limits Clearly define fatigue limits and requirements

Understand strain-to-failure, fatigue, residual stress relationships

Definition of load/thickness limits for WC-Co as done for WC-CoCr

WC-CoCr with hourglass specimens to define S/N curve comparable with WC-Co per JTP?

Keith Legg 847-680-9420

Where does qualification look good?

Commercial no brainer - in production

Military - general likely to work with WC-Co may be near edge of

envelope for WC-CoCr High performance military

(primarily fighters) need to define operational

loads carefully to match qual of existing gear

may need lower hardness, higher toughness material

Full article tests - rig, flight

Keith Legg 847-680-9420

Remaining issues

US-HCAT corrosion testing to be redone obviously testing problem

Fatigue testing of WC-CoCr with hourglass specimens define S/N curve comparable with WC-Co per JTP

Definition of load/thickness limits for WC-Co as done for WC-CoCr