Rowan Technology Group, L

847-680-9420, klegg@rowantech
Website: www.rowantechnology.com 

` Drivers` Technologies

 Chromate-free conversion coatings and ad

promoters

 Chromate-free primers Anodizing  Anodize sealing Plasma electrolytic oxidation Cold spray Design tools for corrosion prediction
Website: www.rowantechnology.com 

` REACH is a big driver in the US because o

international nature of the aerospace and markets

 Potential loss of chromates from market

` EPA proposals for

 Tighter rules on Cr6+ emissions 

 Restrictions on Cr6+ in drinking water

` DoD Cr6+ minimization memo

 DoD depots and program offices encourag

use as far as possible 

 Defense Federal Acquisition Regulations (D

Cr6+ in coatings like primers and sealants, 

conversion coatings – new weapons system
Website: www.rowantechnology.com 

` Most industrial users have gone over to C

treatments for Al , just as in Europe

 Aerospace and defense still mainly use chr In the US one of the most successful has b

developed by Craig Matzdorf and coworke

3⁄4 Also validated for anodize sealing

` Adhesion promoters are proving to be a 

alternative even without inhibitors

 Pantheon Prekote used by USAF

 Boeing uses AC 131 for aircraft OML to pre

3⁄4 AC130 also used as an adhesive bond primer
Website: www.rowantechnology.com 

` Increasing use of chromate-free primers 

composite

 A-64 Apache helicopter uses Deft non-Cr  F-35 uses Deft non-Cr primer Still using chromate pretreat, but working 

non-chromate

 Non-Cr primer beginning to be used on co

aircraft, but less widely used than in Europ

F-35 with Deft 

Enables Moving Production Line

‘Shirt Sleeve’ Maintenance

ASETSDefense 2011
Website: www.rowantechnology.com 

` Frankel, Buchheit, Jaworowski, Swain` Study of how non-chromate primers wor

 Ca, Pr, Zn, Mg, Mo etc.

` Final report will probably be publicly ava
Website: Website: www.rowantechnology.com www.rowantechnology.com 

All r

Cr6

ww

3500 h (primer only)

Chromate BoeAero TC

3500 h (topcoat)

Chromate

BoeAero TC

BoeAero: Crosslink internal formulation BoeAero TC: Crosslink internal formulat
Website: www.rowantechnology.com 

` Kleinschmidt, Mazza, Jaworowski, Blohow` Current non-chromate bond primers do 

robust corrosion inhibition to Al alloys in 

` Tasks 

 Understand role of corrosion in adhesive b Design of tests and samples relevant to bo Testing chromate and nonchromate adhes

systems 

 Create corrosion risk assessment methodo

adhesively-bonded structures 

` Started 2011, end 2015
Website: www.rowantechnology.com 

` Boeing uses boric-sulfuric 

(BSAA), vs Airbus tartaricsulfuric (TSAA)

` Sulfuric (SAA), Thin film 

sulfuric (TFSAA) most widely used in USA

` Navy (Jacksonville) has 

qualified Metalast SAA using controller, with Cr3+sealer for Al landing gear, other components

 Cr3+ sealer energy cost 

saving from lower bath temperature
Website: www.rowantechnology.com 

` Builds up compound layers rather than s

layers

` Tagnite used in US for Mg for many year` Keronite beginning to be used in US for A` Henkel Alodine EC2 is being used in the 

 TiO2-based coating for use on Al and Ti

 Available from vendors Not yet used for aerospace or defense, but 

several applications, including chromate p

` These types of PEO coatings could be pa

for Al wheels and the increasing number components being used in aircraft

Keronite and Tagnite both approved 
Website: www.rowantechnology.com 

` Tagnite from TAG in N. Dakota

 Authorized by NAVAIR for Mg alloys (gearb

when they include Cd-plated inserts and s

` Cold spray using 6061 Al (MIL-STD-132

 Developed by Army Research Lab for Al co

Mg gearbox repair to reclaim damaged gea

` Moog and TAG have developed Tagnite + 

spray combination for Mg gearbox corrorepair and protection 

 Had to develop ways to shield steel inserts

Tagnite process
Website: Website: www.rowantechnology.com www.rowantechnology.com 

` Cold spray 

damage anprint dime

` Finish with ` Equally app

Al compon

 Might wel

Keronite

` May somet

some stren

 Probably 
Website: Website: www.rowantechnology.com www.rowantechnology.com 

Best Dressed Cold Spray Operator Oldest Cold 
Website: Website: www.rowantechnology.com www.rowantechnology.com 

Al substrate

High-P Electroless Ni

Electroless Ni- PTFE }~15 μm

}~15 μm

` Most US suppliers (also Radiall) moving t` Looks pretty good, apparently without ga

problems we had expected

` Users in aerospace and defense will need 

data to show

3⁄4There is no galvanic corrosion issue3⁄4Electroless Ni barrier layer will not lead to 

corrosion of Al if imperfect or damaged
Website: Website: www.rowantechnology.com www.rowantechnology.com 
Website: Website: www.rowantechnology.com www.rowantechnology.com 

` Galvanic corrosion prediction likely to pro

useful when replacing chromate conversiother corrosion-resistant finishes on Al

 How will new finishes and materials interac

` Software from Elsyca NV in Belgium being 

the US under US Navy funding

 Aircraft, ships, vehicles

` Aim is software integrated into CAD desig

check for galvanic corrosion problems durather than fix them later at great expens
Website: Website: www.rowantechnology.com www.rowantechnology.com 

Cd

If water accumulate

connector, corrosi

than standard B11

What if you 

connect an EN 

plated plug to 

a Cd plated 

socket?

Ni

ZnNi

Al backplane

Cd

Al connector shell

ZnNi on socket 

corrodes to protect 

electroless Ni on 

connector

BuWe dahaDado
Website: Website: www.rowantechnology.com www.rowantechnology.com 
Website: www.rowantechnology.com 

` Problem

 Lightweight, high-strength aluminum alloys, such as 7

susceptible to stress corrosion cracking and general coenvironments

 Alloys are typically anodized to increase corrosion resi

fatigue life by up to 40%

` Design

 Equivalent strength to 7050-T74, with 100% improvem

stress corrosion cracking

` Benefit

 Reduce SCC failures and associated maintenance costs Elimination of anodizing process Improved corrosion resistance to allow for trivalent chr

coatings

Extruded bars of prototype alloy
Website: www.rowantechnology.com 

` Problem

 Aircraft wheels are subject to high energy braking 

thermally stable alloys for structural integrity

 Current alloys, such as 2040, can be prohibitively e

the user to use legacy alloys such as 2014

` Design

 Lower-cost compared to 2014 with increased stren

increased thermal stability, increased fatigue perfoequivalent corrosion resistance

` Benefit

 Improved performance compared to 2014 with equ Reduced component weight and increased compon

Photo courtesy of: http://www.goodrich.com/gr-exttemplating/images/Goodrich%20Content/Business%20Content/Aircraft%20Wheels%20and%20Brakes/Product

s/Literature%20Listing/F16%20Block60%20Fact%20Sheet.pdf Half sec
Website: www.rowantechnology.com 

` Comprehensive evaluation and transition 

chromated paint primer

` Corrosion protection mechanisms of rare

compounds based on Ce and Pr

` Scientific understanding of the mechanis

chromate corrosion inhibitors

` Ultraviolet-curable powder coatings` Morphology and mechanism of benign in

http://www.serdp-estcp.org
Website: Website: www.rowantechnology.com www.rowantechnology.com 
Website: Website: www.rowantechnology.com www.rowantechnology.com 

http://www.asetsdefense.o
Website: Website: www.rowantechnology.com www.rowantechnology.com 

ASETSDefense 2012: Sustainable 

Engineering 

for Aerospace and Defens

Rancho Bernardo Inn

17550 Bernardo Oaks Drive

San Diego, CA 92128

http://www.asetsdefense.org/UpcomingWork

August 28-30, 2012

May have half day session on 27th for