March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 1
Advanced Aircraft Corrosion ProtectionA Coatings System Approach
to Reduce Chromates
Joseph H. OsborneBoeing Phantom Works – Seattle
[email protected] 425-237-8518
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 2
Getting the Chromate “Out”
• Reduced Chromate– Choice depends on local regulations
• Key Performance Goal: Long Term Corrosion Protection– Coating system: 2000+ hours neutral salt fog
• Conversion coating: 168 hours
Chromate Conversion Coating
Chromate Primer
Topcoat
substrate
Chromate Conversion Coating
NonChromate Primer
Topcoat
substrate
NonChromate Conversion Coating
Chromate Primer
Topcoat
substrate
NonChromate Conversion Coating
NonChromate Primer
Topcoat
substrate
• Adhesion Promoters• Don’t meet MIL-C-81706
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 3
Requirements for Successful Technology Transition
Meet Performance Requirements– Capable Engineering properties
• Meet performance specifications– Adaptable Processing characteristics
• Appropriate for production environment
Specification coverage– Technical Order / Military or industry specifications
• What are the “real” performance requirements?– Current specification limits– Equal or better than today’s coating systems
• Safety of personnel and airframe/vehicle is prime concern
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 4
Overview
• AACP program– Goals– AC-131/Boegel– Performance data– Producibility data
• Other applications– Painting– Bonding
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 5
Program Description
• Funded by Aging Systems Command/AFRL– Aging Aircraft Office (ASC/AAAV)
• Transition Demonstration of coating system– Topcoat technologies developed for C-17 (APC)– Nonchromate Conversion Coating technologies developed by
AFOSR/AFRL/DARPA (Boegel/AC-131)• Program Plan
– Phase I: Laboratory validation of performance and process – Phase II: Flight test
• Coat test vehicles, summer 2004
• Deliverables:– Coating system description– Laboratory validation data– Analysis of flight testing– Processing description for T.O. 1-1-8
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 6
AACP Coating System
Flight Operations
DepaintDepot
MaintenanceRepaint
Repaint
Clean & Seal
Alkaline Clean
Brighten
Conversion Coat
(AC-131)
Prime & Paint
(Cr primer,APC Topcoat)
• Cleaning steps determined by conversion coating– CCC requires active “bright” metal surface– AC-131/Boegel adheres to surface oxides
• Doesn’t require brightener process• Does require clean waterbreak free surface
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 9
Performance and Producability Verification
• Boegel EPII• Cleaning and Brightening• Depainting• Corrosion and weathering data
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 10
AC-131/Boegel conversion coating
• Boegel is Boeing Developmental name – Licensed to AC Tech
• AC-131 (painting), AC-130 (bonding)
• Mixed Zr/Si oxide system• Silane coupling agent chosen to match primer, sealant, or
adhesive chemistry– AC-131/Boegel-EPII is epoxy functionalized – epoxy primers/adhesives– Boegel-AM is amino functionalized – polyimide adhesives
• Water solution -- ~3-5% solids• Spray on, no rinse, ambient dry• Little or no waste
– Neutralize and sewer• Superior adhesion
– Aluminum, titanium, CRES• Common surface preparation
• “pigmentable” for corrosion protection and optical properties
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 11
AC-131/Boegel EPII
• Optimized for adhesion of epoxy coatings – Superior adhesion to Al, Ti, CRES
• A water-like solution with reactive ingredients– Long shelf life, 12 hour pot life once mixed– 2 part kit, prepare amount needed for job
• Spray applied to part/airplane– “spray drench”
• Solution flows off part– “dripless spray”
• Apply to wet surface but minimize drainage
• Dry in place, no rinse required– Thick coatings reduce paint adhesion
• Remove drips and solution from pockets and recesses
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 12
Large volume applications
• BCA Paint Hanger Trials– Replacement for Alodine 1000– Meets production engineering
reqmt’s on new clad aluminum fuselage
• Production Laboratory Testing– Ability to mix and use– Process compatibility with masking and
equipment – Ability to Strip– Paper/Tape compatibility– Compatibility over Composites– Wet/Dry Adhesion– Corrosion
• Sandwich • Filiform• Salt Spray
– Rain Erosion– Forward and Reverse Impact– Acrylic Crazing– Titanium Stress Corrosion– Hydrogen Embrittlement
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 13
Inspectability of Boegel/AC-131
• Dyes and fluorescents• Good color definition with dyes• No effect on adhesion performance• Weatherability/cleanability data to be developed
Alodine1200S
AC-131 withWater Soluble dyesAC-131
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 15
Process Schemes with AACP System
• Alkaline clean / brighten / AC-131 / Prime&Paint– Eliminates chromate conversion coating– Reduces rinse water (no rinse after AC-131/Boegel)– Meets current engineering requirements
Clean & Seal
Alkaline Clean
Brighten
Conversion Coat
Prime & Paint
Clean & Seal
Alkaline/acid Clean
Conversion Coat
Prime & Paint
• “detergent” clean / AC-131 / Prime&Paint– Eliminates chromate conversion coating– Eliminates brightener step and associated rinses– Shows promise – need to define cleaning process
“Low
Ris
k”
“Str
etch
Goa
l”
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 16
Depainting
0
5
10
15
20
25
PR 3133(Ammonia)
PR 5044(Peroxide)
PR5000 / PR3170(Peroxide /
Solvent)
TRP Inc. ES-1(MeCl2 / Formic
Acid)
Ho
urs
(80
-100
% P
rim
er R
emo
val)
Alodine / MIL-PRF-23377 Alodine / MIL-PRF-85582
Boegel EP II / MIL-PRF-23377 Boegel EP II / MIL-PRF-85582
AA2024
0
5
10
15
20
25
PR 3133(Ammonia)
PR 5044(Peroxide)
PR5000 / PR3170(Peroxide /
Solvent)
TRP Inc. ES-1(MeCl2 / Formic
Acid)
Ho
urs
(80
-100
% P
rim
er R
emo
val)
Boegel EP II / MIL-PRF-23377 Boegel EP II / MIL-PRF-85582
Ti –6,4
• Does not “depaint” like conventional systems– Topcoat removes first from primer– Additional dwell time or manual effort needed to remove primer
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 18
ACRAC Coatings at 5688 Hours NSS
• AA2024-T3 substrates
Chemidize/Boegel/85582/APC-g
CB82G
Boeclene/Alodine/85582/APC-g
BA82G
Boeclene/Boegel/85582/APC-g
BB82G
Boeclene/Alodine10PW22-2/APC-g
BA10G
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 19
ACRAC ASTM B117 Salt Spray – 2500 hrs
MIL-PRF-85582Deft 99-GY-001
Alodine 1200S AC 131
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 20
ACRAC ASTM G85-A5 “Prohesion” – 2500 hr
MIL-PRF-85582Deft 99-GY-001
Alodine 1200S AC 131
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 21
Weathering Data at 1500 Hours
0
1
2
3
4
5
6
7
8
9
Akzo10P20-4/ECW-104
Deft02Y040
Deft44GN72
SWE90G203
Akzo10P20-4/ECW-104
Deft02Y040
Deft44GN72
PRC1432GV
PRC1432GV &
Deft02Y040
SWE90G203
60°85°DeltaE
Deft 03-GY-321 Deft 99-GY-001
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 22
Specification Summary
Spec # Process Implementations
BAC5663 Aluminum Alloy Conversion Coating for Paint
BCA-Fuselage rivets(737 console)(final paint)
D950-10313-1, Rev C; BSMS-25-002; BSPS-07-002
Titanium Alloy Conversion Coating for Paint
F-22
BSMS-25-001; BSPS-07-001, HP 4-136 Rev A; D950-10413-1 Rev A, D720PM-PP006, Rev A; S697-10090-1 Rev A; 5PTPHB25; Assorted DoD TOs
Titanium Alloy Adhesive Bonding
F-22; X-32; B-2 spares; Delta IV; AH-64; F-22; CH-47; CH-46
D210-13577-1; SRM 51-70-09; SRM 51-70-10; Assorted DoD TOs
Aluminum Alloy Adhesive Bonding
CH-47, Airline SRMs, C-5
HP 4-136 MRB Stainless Steel Adhesive Bonding
AH-64
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 23
Adhesion to Boegel-EPII Coated Rivets
Depainting
Rain ErosionAC-131 coated
Scribed – wet tape
“Rivet Rash”
•Clad Fuselage skins•“leached” rivets
OTS
AC-131
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 24
F-22 Forward Boom
• Phosphate-fluoride is typical conversion coating for titanium
• Process tanks not available, so different approach was needed.
• First application– AV #2– 1997
• Current:– Forward & aft booms– Titanium tubes
HF/HNO3 etch Phosphate fluoride Boegel
goodpoorpoor
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 25
Titanium bonding
• B-2 Ti core to composite• Replaces chromic acid anodize
• X-32 Ti-Ti, Ti-composite• F-22
–Aft Boom composite reinforcement–Studs for insulation blanket installation–Repair/reinforcement of structure
• Delta IV Ti-composite end fittings
• Helicopters–Comanche (RAH-66) rotor caps,
components
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 26
737 Aisle Stand Frame Cell
• Produced at Boeing-Portland– AA7075 parts are currently anodized and painted in
separate facilities– BMS10-11 primer, Nextel Suede finish coat– Cell designed to produce frames in a dedicated line
• BAC5663 Released– Mechanical (grit blast) and chemical deox– Boegel EPII processing is the enabling technology
• Replaces anodizing– Estimated benefit
• Run time reduced by ½• Flow time reduced from 27 to 2 days
• Implementation Strategy– Probably drawing change
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 27
Process Name: AISLE STAND FRAMECELL
Model Number: 737Model Name:
Scope ofOperations
Standard Work Sheet
From: Raw Material to finished painted part and in
To: Stores in two days
Date:
Dept. Head Supervisor
QualityCheck
SafetyPrecaution
Standard Workin-process
#. of pieces of std.work in-process
TAKTTime
OperatorNumber
incoming
fromT-20
Goals
TabRemovalStraighten
DrillTap
Penetrant
Bo
e-g
el
ap
plic
atio
n
PartMark
737 Monthly Rate 14 PlanesDaily Requirement 3.5 Parts
Takt Time = 137 Min.70 Parts Per Month
Customer Requirements
MaskHandFinish
Clean
Sandblast
2nd shift operationavailable for additional
part numbers
outgoing
PaintBooth
254A1307-1254A1237-2254A1237-4254A1238-3254A1239-3
= ship set
C/T 5 minC/T 1 minC/T 10 minC/T 1 min
C/T 45 minREF. QA op
C/T 2 min C/T 2 min C/T 2 minC/T 2 min C/T 2 min
C/T 2 min
Bo
e-g
el D
wel
llo
cati
on
Boe-gel resttime = 60 min
27 flow days reducedto 2 days @ a one
shift operation
134 minutes for firstpart through the line
Total touch time =74 minutes
Planning standards =29 minutes
9/20/02
Aisle Stand Flow Diagram
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 28
OC-ALC Backshop Demonstration
• Coated several parts in TF-33 refurb shop • February 18, 2004
– Glen Graham is technical point of contact– Evaluate potential for work cell environment
• TF-33 cowl– Scuff sand/overcoat application
• Needed cleaning to waterbreak free condition• Scrap part, not painted
• Engine support assembly (??)– Titanium panels, stainless rails, aluminum brackets– Cleaned to WBF, coated, 2 hour dry, prime
• Miscellaneous aluminum brackets– Racked for painting, coated, 2 hour dry, prime
• not cleaned well, showed orange peel (marginally acceptable)
March 8-11, 2004 2004 Air Force Corrosion Program Conference Slide 29
Conclusions
• AC-131/Boegel EPII coating systems are capable for depot and field processing environments– Performance equivalent to present systems
• Chromated primer is still required– Superior adhesion to aluminum, titanium, and stainless steel– Colored for process and in-process and end-item inspection– Potential to eliminate aggressive brightening
• Reduction in process steps and processing time– Potential to provide stand-alone corrosion protection
• Ongoing inhibitor incorporation work.
• Flight testing in AACP program will validate performance capabilities for mold line use– Language for T.O. 1-1-8 for implementation
• Other potential painting and bonding applications– Adaptable to multiple part configurations and work cells