Technological tests regarding the qualification of the REACh compliant surface treatment processes for helicopter dynamic systems

(1)

TECHNOLOGICAL TESTS REGARDING THE QUALIFICATION OF THE

REACH COMPLIANT SURFACE TREATMENT PROCESSES

FOR HELICOPTER DYNAMIC SYSTEMS

A. Güzel

1*

_{, S. Heredia}

2

_{, J-M. Besson}

2

1

_{Airbus Helicopters Deutschland - Industriestraße 4 - 86609 Donauwörth – Germany}

2

_{Airbus Helicopters France - Aeroport Marseille/Provence - 13725 Marignane cedex -}

France

*_{Corresponding Author:}

E-mail: ahmet.guezel@airbus.com - Phone: +49 (0) 906 71 8535

Abstract

REACh regulation imposes to European industrial companies to apply viable alternatives for the components which contain hexavalent chromium from 2017. Hexavalent chromium is mainly used in surface treatment operations, which affect the strength relevant properties of the helicopter components, such as the fatigue behaviour as well as the resistance against wear, fretting and corrosion. The components of the helicopter’s dynamic system treated by alternative surface treatment processes have to be certified after the qualification of the REACh compliant processes.

This paper presents a technological test program used for determining the performances of the proposed REACh compliant surface treatment processes compared to the current ones. One key issue for the dynamic system components is the contact between two components for which new surface treatments will be applied. In order to determine the contact pairs to be tested, a complete screening of the critical components of the dynamic system has been performed, whose failure is catastrophic (e.g. rotors, gearboxes, etc.), and representative technological samples have been designed. This technological test program includes the fretting wear tests for different plane to plane contacts, fretting fatigue tests in cylinder to cylinder contacts, corrosion tests inside bolted connections and the combined wear-corrosion tests. The principle is to compare each time the current design with the REACh substitutes. Depending on these tests results, some complement can be done in case of differences observed or some additional specific tests can be required based on the service experience coming from the development and/or major incidents. The results of the technological test provide not only a performance check required for the certification of the REACh compliant products, but also an extensive experimental knowledge on the fatigue, wear, corrosion and fretting resistance of the materials used in the aerospace industry.

1. INTRODUCTION

REACh (the Registration, Evaluation, Authorization and Restriction of Chemicals) is a European regulation managed by the European Chemicals Agency (ECHA) based in Helsinki, Finland. The purpose of this regulation is three-fold:

 To ensure a high level of protection of human health and the environment from the risks that can be posed by chemicals,

 To promote alternative test methods,

 To support the free circulation of substances on the internal market.

Manufacturers putting products on the market in the European Economic Area (EEA) have to ensure that they follow all obligations put in place by the REACh

regulation. Challenged by the REACh requirements, Airbus Helicopters is fully committed to the progressive retirement of Substances of Very High Concern (SVHC) -in particular Hexavalent Chromium- from all aircrafts, products and manufacturing processes.

Complying with REACh regulation is not only an important requirement for the entire aerospace industry, but it is also an opportunity for the companies -and also for their suppliers- to demonstrate their commitment to safety in products and operations for the benefit of employees, customers and the environment. Therefore, besides contributing to the common goal of a protected environmental future, Airbus Helicopters takes the process of implementation of REACh compliant substances as an opportunity to improve its

(2)

processes a This paper used for d proposed processes c 2. AIRBUS SUBST Two official Airbus Helic  Anne bann  Cand candi According t Annex XIV prohibited. candidate li as the appr is modified has started processes suppliers in appropriate To ensure REACh pro established Hazardous team dedica line with RE Airbus Hel consists o Preparation Figure 1). Table 1: Te 1 2 3 Chromi 4 5 6 7 8 M 9 10 and products presents a determining REACh co compared to S HELICOPT TITUTION PR REACh list copters: ex XIV: Lis ed on a defin didate list: L idate to be b to this, for a and candid For running ist substance ropriate alter and the su .The subjec is organize n order to e eradication timely and cess and tim a transv Material (H ated solely t EACh require licopters’ R of three ph ns, Impact An echnical Wor Cad ic Acid Anodiz Chrom Alumin Chromate Ma Manufacturing Corro 4 s. a technologic the perfor ompliant su the current o TERS’ REAC ROCESS s are of mai st of subst ned date (su List of subs banned in the any new air date list subs g programs, es shall be r rnatives are upply chain ct of convert d in collab ensure the of hazardous effective a meline, Airbus versal orga HazMat) Pro to coordinate ements. REACh subs hases: Reg nalysis and rking Groups mium Plating Hard C zing for Corros mic Acid Anod nium Chromat e Painting Prim agnesium Chro processes: Tr osion Protecti Chromate 41st_Europea

cal test prog rmances of rface treat ones. CH in importanc tances that nset date). stances that e next years. craft, the us stances sha Annex XIV replaced as qualified, de implementa ting supply c oration with progressive s substances dherence to s Helicopters nization – ogram – wi e the activitie stitution pro gulatory Su Substitution for Substitut Topic + Chromium V Chromium Plat sion Protection dizing for Bond

te Conversion mer P05/P20 & omate Conver richloroethylen ve Sealant Ma e Bonding Pri an Rotorcraft gram f the ment ce for are t are se of all be and soon esign ations chain h the and s. o the s has the ith a es in ocess rvey, (see Figu The Heli subs impa used Bas subs subs         In repla cons tech with grou elim date tion. VI Passivation ting n + Dichromat ding Applicatio n Coating (CCC

& Wash Prime rsion Coating ne, Sulfochrom astinox 6856K mers t Forum 2015 ure 1: Globa HazMat copters’ Reg stances imp acted prepar d in Airbus H ed on Re stances hav stitution: Trichloroeth Chromium ( Sodium dic Potassium d Dichromium Strontium c Potassium Pentazinc c addition to acement fo sidered a p hnical workin the substitu up will ensu minated in ac e and sunset n te Sealing (CA on C) er P15 mic Pickling K 5 l Substitution Program h gulatory Surv pacted) and rations conta Helicopters’ s egulatory S ve been id hylene (VI) trioxide hromate dichromate m tri(chromate hromate hydroxyoctao chromate oct o these or surface priority by A ng groups w ution of impa re that the c ccordance w date listed in Last Ap D 21.0 21.0 AA) 21.0 21.0 21.0 22.0 21.0 21.1 22.0 22.0 n Process. has comple

vey (the ide d the iden aining those site. Survey, the dentified as te) oxodizincate tahydroxide substances, treatment Airbus Helic were establis acted prepara concerned s with the fina

n the table b Application Date 03.2016 03.2016 03.2016 03.2016 03.2016 07.2017 03.2016 10.2014 07.2017 07.2017 eted Airbus ntification of ntification of substances e following priority for edichromate Cadmium s is also copters. Ten shed to deal ations. Each substance is l application below. Sunset Date 21.09.2017 21.09.2017 21.09.2017 21.09.2017 21.09.2017 22.01.2019 21.09.2017 21.06.2016 22.01.2019 22.01.2019 s f f s g r m o n l h s n

(3)

Here, the “Last Application Date” defines the date by which applications for authorization must be submitted to allow continued uses after the sunset date until a decision on the application for authorization is taken, whereas the “Sunset Date” is the date from which placing on the market is prohibited unless authorization is granted.

In the following section, processes in the working groups mentioned above, their application areas as well as their REACh compliant potential substitutions are mentioned briefly.

2.1. Technical Working Group 1

This technical group includes the substitution of cadmium plating with chromium VI passivation including local touch-up by brush plating, which is mainly applied for corrosion protection, especially in dynamic components and fasteners.

Since this process includes substances such as Chromium trioxide and Sodium dichromate substances, it has to be replaced by a REACh compliant substitute.

The selected alternative is similar to cadmium plating in performance (in particular, in corrosion, thickness ranges, local touch-up feasibility, etc.) and needs to be associated with friction control lubricant on fasteners. The deployment in the supply chain is under analysis.

In this technical group, the replacement of hard chromium plating is investigated. The process is applied for the purpose of fretting and wear protection. For several applications, alternative solutions are already qualified: hard coatings deposited by thermal spray. The current in-progress approach for these alternatives is to select the best candidates and launch the design changes.

Chromic Acid Anodizing (CAA), dichromate sealing including local touch-up by brush anodizing is mainly applied for corrosion protection of light alloy parts (with or without painting). The process contains Chromium trioxide and Potassium dichromate. For new programs, an alternative solution standard associated with Chromate sealing, is already qualified and used already since several years for some applications. The second step, which is under investigation, is to associate this anodizing with Chromate-free sealing. Associated local touch-up by brush anodizing are under evaluation.

For running programs, with the objective of having less impact on the supply chain, two thin film anodizing methods are under investigation.

This technical group includes the substitution of Chromic Acid Anodizing for bonding applications used mainly for light alloy corrosion protection for structural bonding. The process includes Chromium trioxide to be eliminated.

For structural bonding of such parts, an alternative anodizing process which supplies adequate properties to replace Chromic Acid Anodizing (CAA) prior to bonding primer application is under qualification in Airbus Helicopters plants. The deployment in the supply chain is under analysis.

In this technical group, the replacement of Chromate Conversion Coating (CCC) is investigated. The process is applied for surface preparation of light alloys before painting and includes Chromium trioxide as well as Dichromium tri(chromate) (for touch-up) to be eliminated.

Here, alternative processes were identified, have been tested for replacement of CCC process.

In this technical group, the replacement of chromate painting primer & wash primer is investigated. These primers that contain Strontium chromate, Potassium hydroxyoctaoxodizincatedichromate and Pentazinc chromate octahydroxide are to be eliminated. Today, chromate painting primers are used for application on metallic parts (aluminium, magnesium, steels, titanium, stainless steels) to not only ensure corrosion protection on single parts, but also to provide electrical isolation in assembly, and mechanical protection during maintenance and assembly. The alternative must guarantee the same level of performance. This is a real challenge that leads common efforts between Airbus Helicopters and paint suppliers. In association with paint suppliers, the first screenings of alternatives have been performed and two different chromate-free high solid products were selected for the qualification process. In parallel, other emerging products are under evaluation.

Chromate wash primer has also a large scope of applications on metallic parts not only for adhesion but also for corrosion protection. Here again, the first screenings of alternatives have been performed with paint suppliers and two different chromate-free products were selected for the qualification process.

Magnesium Chromate Conversion Coating including local touch-up applied mainly for corrosion protection and surface preparation before painting. The process contains Potassium dichromate to be

(4)

eliminated. For the r Conversion conversion 2.8. Tech In this te Trichloroeth Sulfochrom are inves Trichloroeth respectively For some been replac Sulfochrom under qualif For main T solutions ar 2.9. Tech This techni chromic sea assemblies Mastinox is strontium ch a chroma manufacture 2.10. Tech This techni Chromate B which includ MB 6726 i alternatives investigation 3. COMPA SUBST Global equi and their demonstrate technologic paper dea dynamic sy included in t The qualific on by the A Processes finding the current one qualification qualification affected com that purpo compliant s the technolo replacement Coating sev products are hnical Worki echnical gr hylene and ic etching ap stigated. T hylene an y, which shou applications ced and im ic etching b fication phas Trichloroethy re qualified a hnical Worki ical group alant Mastino as a sea s a chromate hromate. Thi ate-free pr er. Implemen hnical Worki ical group Bonding Prim de strontium is now repl s to repla n. ATIBILITY A TITUTES BY valence of th REACh ed by t al test progra ls only wit ystems. Airf this work. cation proces Airbus Helico (LMP). This most conve e following n of the new n of the proce mponents ha se, the pe surface treat ogical test pr 4 of Magne veral chromiu e under evalu ing Group 8 roup, the d the r pplied for su hese treat nd Chrom uld be elimin s, Sulfochrom plementation before CCC se. lene applica and implemen ing Group 9 includes the ox applied al lant for gal e-based seal s sealant is roduct from ntation is in p ing Group 1 includes the mers MB 67 m chromate t aced by EC ace BR 1 ANALYSIS O TECHNOLO he current su compatible technologica am which is th the com frame comp ss of the sub pters’ Labor s department nient proces a specifica w process. In esses, the q as to be ens erformance ment proces rogram. 41st_Europea esium Chro um-free chem uation. replacement eplacement rface prepar tments co mium Trio ated. mic etching n is in prog and CAA is ations, altern nted. e substitutio lmost in all o lvanic corro ant and incl now replace m the s progress. 0 e substitutio 726 and BR to be elimina C 3909. Se 27 are u OF THE OGICAL TES urface treatm substitutes al tests. presented in mponents of ponents are stitutes is ca atory Materia t is in charg ss to replace ation and to n addition to ualification o ured as well of the RE sses is teste an Rotorcraft mate mical t of of ration ntain oxide has ress. s still native on of of the osion. udes ed by same on of R127, ated. veral under STS ments s is The n this f the e not arried als & ge of e the o do o the of the l. For EACh ed by A c com rega com corr Figu subs The the curr prog     The surfa haza alter issu com prod corr dete of th In o work prop treat tech     Eac frett wea t Forum 2015 hange in th mponents of arding the mponent, in osion occurr ure 2: Qual stitutes. aim of the p performance ent ones by gram include The wear (f The corros different co The combin The fretting principle is ace treatm ardous subs rnatives. The ed from a mponents of ducts. After l esponding m ermined. The he contact pa order to anal king environ perties, whi tments, four hnological tes Fretting wea Fretting fati Fretting fati Specific tes h test has a ing fatigue li ar and corro 5 e surface tr a helicopter performan particular ence as well ification proc proposed tes e of the ne y coupon te s specific tes fretting wear) sion inside ntacts, nation of the fatigue. to compare ment proce tances, with e different te a screening the dynam listing the af material pair e most repre airs were the

yse different nments and ch can be r different te st program: ar: “Pin on d gue: Clevis T gue and corr sts if required specific goa fe limit deter osion resist reatment of r is an imp nce of th in wear, f l as fatigue b

cess for the

st program is ew treatmen ests. The pr sts for the an ) for different bolted con wear and co e each time ess, which h their REAC ested config g of the mic systems ffected comp rs to be ana esentative m en tested. t contact pa d different e affected ests are incl

isc” Test rosion: Clevi d

al: the wear a rmination, th tance estim mechanical portant issue he affected fretting and behaviour. e alternative s to compare nts with the roposed test nalyses of: t contacts, nnection for orrosion, the current h includes Ch compliant urations are mechanical s of all the ponents, the alysed were material pairs airs, different mechanical by surface luded in the s Test analysis, the e cumulated ation. Each l e d d e e e t r t s t e l e e e s t l e e e d h

(5)

time, the co treatment substitute p 3.1. Frett The aim of of the two possible to not REAC accordance These tests available at test principl Figure 3: Fr Here, a pla sample. In t contact is re During test relative dis frequency. representat conditions a way, it ca pressure o investigation frequency fo The wear re is analysed (1) During force, the coefficient identified by during the te Figure 4: Id omparison b process a process is pe ting Wear Te this test is t materials in compare th Ch, to the e with REACh s are realize

the test labo e. retting wear ane pin is p this way, a re ealised. t, a normal splacement  The nor ive. For t are precised an correspo of the mec n. The test or predefined esistance of in two ways the test: imposed dis are recorde y the evolut est as a func dentification o between the nd its RE rformed. est to identify th n contact. In he actual tre e proposed h requiremen ed using the oratory. Figu test principle put in conta epresentative force P, is , is impose rmal force this reason for each pai nd to the chanical com t is perform d number of the investig : The normal splacement ed. A coatin tion of the fr ction of time. of the coating existing sur EACh comp e wear resp n that way, eatment whic d treatment nts. fretting mac re 3 present e. act with a p e plane vs. p s applied an ed with a g has to n, the loa rs of tests. In specific co mponents u med at a ce cycles. ated contact l and tange

and the fri ng wear can riction coeffi g lifetime. rface pliant onse it is ch is t in chine ts the plane plane nd a given be ading n this ntact under ertain t pair ential iction n be icient (2) by m of th prof Figu Pin surfa give Figu The wea 3.1.1 Perf cons the the high as lo Figu coef subs coef simi A si Ano subs proc proc pairs and After the te means of a 3 he plane sa ile. ure 5: Wear p wear volum aces before en in the follo ure 6: Wear v overall wea ar volumes. 1. Friction formance of sidered as e friction coeff friction coeff her than the

ong as it is e ure 7 illustra fficients of C stitues. It fficients of lar to the Ca milar compa dizing (CAA stitues. As cesses are cess (see Fig

s additional assembly te st: the wear 3D interferom mple is calc profile meas e is quantifi and after th wing sketch. volume of the r volume is n Coefficient the REACh equivalent to ficients are ficients indu one induced quivalent in w ates the com Cadmium pla can be s the substitu dmium plate rison was do A) process ve a first imp promising gure 8). How investigatio ests are need

r resistance metry. The w culated from

ured after th ied from pic he test. A d .

e pin. then the sum

t Analysis h compliant o the current in the same ced by the d by the actu wear. mparison of ated surface seen that ute plated s ed ones. one for the C

ersus its two pression, the alternatives wever, for so ons by mea

ded for a fina

is quantified wear volume the surface e test [1]. ctures of the escription is m of the two substitute is treatment if e range or if substitute is ual treatment f the friction es and their the friction surfaces are Chromic Acid o alternative e substitute s for CAA ome contact ns of clevis al statement. d e e e s o s f f s t n r n e d e e A t s

(6)

Figure 7: Cadmium contact p titanium/ste Figure 8: Chromic A alternative s Comparison versus alt pairs: (a) el contacts. Comparison Acid Anodiz substitutes. 4 n of friction ternative su steel/steel n of friction zed surface 41st_Europea n coefficient ubstitute p contacts, n coefficient es versus an Rotorcraft ts of lated (b) ts of two 3.1.2 Con pairs follo Figu and titan Figu func calc the this, Cad subs wea sam titan of th Mea subs The surfa were illust alter diss alum conc rate In F is tre Cad show treat rate alter Titan subs Mea all s wea t Forum 2015 2. Wear Ra ncerning the s with the co owing results ure 9: Comp substitute p nium/steel co ure 9a, prese ction of the c ulated by the cummulated the highes mium/Cadm stitute subst ar rates, for me analysis nium as well. he when the asured wea stitute substa wear rates o aces versus e also analy trates the w rnative subst ipated energ minium vers cluded that s. igure 10b, th eated with a mium and a wn. Here tments are s when ther rnative plated nium vs. a stitute subst asured wear substances s ar rates when 5 ate Analysis wear rates orresponding are reported arison of the platings: (a) ntacts. ents the calc contact pair. e measured d dissipation st wear rat ium contact. ance in the the same t is performed Figure 9b i e contact pa r rates is ance than for of the Chrom their REAC ysed in the wear volume titutes as a fu gy for homo us aluminiu

all are equ he wear rate lternative su alternative su again, the equivalent t re are in co d steels. luminium co tance) is co rates are ve show equival n they are in s s of the tes g surface tre d. e wear rates steel/steel c culated wea . Here, the w wear volum n energy. A te is observ . The introdu contact lea testing param d for the co illustrates the ad is made again sma r the Cadmiu mic Acid Ano Ch compliant same way. es of the CA unction of th ogeneous c um contacts uivalent rega e of the alum urface treatm ubstance pla e alternativ to CAA reg ontact with C ontact (with ompared in ery small. In lent behavio contact with ted material eatments the of Cadmium contacts, (b) r rates as a wear rate is e divided by According to ved for the uction of the ads to lower meters. The ontacts with e wear rates of Titanium. ller for the um. odized (CAA) alternatives Figure 10a AA and the e cumulated contacts, i.e. . It can be arding wear minium which ents against ted steels is ve surface arding wear Cadmium or h CAA and Figure 10c. n that sense, ur regarding titanium. l e m ) a s y o e e r e h s . e ) s a e d . e r h t s e r r d . , g

(7)

Figure 10: substitutes aluminium/s pairs. 3.2. Frett The aim of contact bet fretting fatig compare s alloys, Cad concerned in accordan Figure 11: and experim Figure 11a testing. Bu passivated Wear rates for: (a) steel and (c ting Fatigue this test is t tween a clev gue. In that serial treatm dmium platin by REACh w nce with the R

a) Schemati mental device illustrates ushings insid stainless ste s of CAA an aluminium/ c) aluminium Test to identify th vis and a bu t way, it wil ments (CAA ng on steels with new su REACh legis c illustration e, b) applied

the test sam de the lugs eel, which a nd the prop /aluminium, /titanium co e behaviour ushing rega l be possib A on alumi etc.) which urface treatm slation. of the spec fatigue load mple utilized s are mad are placed in osed (b) ntact r of a rding le to nium h are ments cimen ing. d for e of nside the appl inter fatig each limit are The Gau pres func spec can equi fatig A s subs show alter curr frett Figu with subs lugs with ce lied to the c rface betwee gue load is i h 1 Mcycles ts of differen evaluated in results are ussian repa sented for th ction of the cimens and be seen ivalent to C gue loading o similar resu stances of ws that the rnative subs ent CAA tre ing fatigue lo ure 12: Gaus fretting of: a stitute, b) CA ertain interfe clevis sampl en the bore ncreased on (Figure 11b) t material co a cylinder/cy e illustrated rtition of t he statistical mean fatig the scatter that the admium plat on clevis (see lt is obtain CAA in Fig fatigue lim stitutes are atment. The oading. ssian reparti a) Steel plate AA and the tw erence. A fat le until it br and the bu n many leve ). In this way ombinations ylinder conta in Figure 1 the fatigue comparison gue limit of factor of th selected s ating in term e Figure 12a ned for the gure 12b. T mits with fre higher than ey are both ition against ed with Cadm wo other sub tigue load is rakes at the ush. Applied ls, e.g. after y, the fatigue with fretting act. 12. Here, a results is n, which is a f the tested he results. It ubstitute is ms of fretting a). e alternative The analysis etting of the that of the better under fatigue limit mium and its bstitutes. s e d r e g a s a d t s g e s e e r t s

(8)

3.3. Frett The aim o corrosion re in a single fretting thr bushings. M clevis and w is done par corrosion of can be dete Figure 13: and applied In performin loads repres After comp disassemble spray for s Then, the s with same t are increas complete fa The tests a The results surface trea contacts w aggressive 3.4. Spec Especially environmen the test pro containmen designed, in partially with the surface environmen corrosion p observed a some furthe the effect ting Fatigue of this test esistances of test. The t rough conta Moreover, we washers can rtially under f the whole ermined. Schematic d fatigue load ng this test, f sentating the pleting this ed from the some predef system is ass tightening pa sed. This b ailure of any p and their eva s will revea atments of t working unde

environment

cific Corrosi

for the par nts, some ad ogram. In or nt on corrosio n which the h a containm e. The part nt. The nucle its undernea at certain t er specific te of different 4 and Corros is to comp f different su est allows f act betwee ear through n be observe salt spray e system as a illustration o ding with salt

fatigue loadin e flight loads block, th bench and e fined hours sembled aga arameters. T block is rep part of the as aluation are al the perfo he assembli er dynamic tal conditions ion Tests rts working dditional tests rder to analy on, a specia surface of a ment sheet w is exposed eation and th ath the conta

time interva ests for the surface tre 41st_Europea sion Test pare fatigue urface treatm for analysing en screws contact betw ed. Since the

environment a function of of the spec spray expos ng is applied s during N cy e specimen exposured to (see Figure ain on the b The fatigue l peated until ssembly. still in prog ormance of ies with com

loading an s.

under corro s are include yse the effe al test setup a part is cov with certain ga d to a corro he growth o ained surface ls. Furtherm determinatio eatments on an Rotorcraft and ments g the and ween e test t, the time cimen sure. d with ycles. n is o salt 13). ench oads l the ress. f the mplex nd in osive ed in ect of was vered ap to osive of the e are more, on of n the galv with tech tests resu for unde 4. A te dete REA com test diffe tests insid corr time The test Trib   Fret   In a are dete of t pres com alter The meth treat are the tech t Forum 2015 vanic corrosio dissimilar m hnological te s mentioned ults will revea the corrosio er investigati SUMMARY echnological ermining the ACh compli mpared to th program in erent plane s in cylinder de bolted co osion tests. e the current following co results perfo bological be The selecte performs b regarding th Concerning aluminium, equivalent However, s of assemb differences contacts. tting fatigue The selecte at least regarding th The two alt than CAA fo addition to th in progress ermining frett the assemb sented in th mparison o rnatives of th presented hodology fo tements wit very benefic alternative hnological te 5 on of the pa materials, a est program d above are al the perform on resistanc ion. AND CONC test progra e performan ant surface e current o ncludes the to plane co to cylinder c onnections a The princip design with t onclusions ca ormed so far: havior: ed substitut better than he friction an the surfa alternativ to CAA ome further bly tests in friction e resistance ed substitute equivalent he fretting fat ternative sub or fretting fat hese results, , the results ting, wear an blies. All t is paper wil of different he different te technologica r substitutin h the enviro cal to compa e processe ests provide arts, which ar re also incl .The specif e still in pro mance of the ce of the CLUSIONS ram was pr nces of the e treatment ones. This te fretting we ontacts, fret contacts, co and the com ple is to co the REACh s an be done b : te for Cadm Cadmium p nd wear prop ace treatme ve substi for wear investigation are require coefficient : e for Cadmiu to Cadmi tigue resista bstitutes are tigue resistan , numerous s of which w nd corrosion the technolo ll be perform t surface echnical wor al test progr ng the exist onmentlly fr are the perfo es. Moreo deeper info re in contact uded in the fic corrosion ogress. The e substitutes components resented for e proposed processes echnological ar tests for tting fatigue rrosion tests mbined wear-mpare each substitutes. based on the mium plating plating itself erties, ents of the tutes are properties. ns by means ed due to s of some um plating is um plating nce, e both better nce. further tests will allow for resistances ogical tests med for the treatment rking groups. ram and the ting surface riendly ones ormances of ver, these ormation on t e n e s s r d s l r e s -h e g f e e . s o e s g r s r s s e t e e s f e n

(9)

the fatigue properties of different materials with different surface treatments as well as on their resistance to fretting, wear and corrosion, which make it possible to improve the design activities of the current products and the new developments.

5. REFERENCES

[1] S. Fouvry, C.Paulin, S. Deyber, Impact of contact size and complex gross-partial slip conditions on Ti-6Al-4V/Ti-6Al-4V fretting wear. Tribology International, 2008.