Stress distributions in plasma-sprayed thermal barrier coati(9)

Stress distributions in plasma-sprayed thermal barrier coatings as a function of interface roughness and oxide scale thickness

M.Ahrensetal./SurfaceandCoatingsTechnology161(2002)26–3535

nesses.Noresultsforseparatevariationsofpeakheightandpeakdistancearepresentedthere.

Comparablecalculationsconcerningthelocaldepend-encesofstresslevelswereperformedinw15xbymeansofadifferentmathematicalapproach.Thegeometryusedformodellingtheinterfaceroughnesswasslightlydifferenttooursine-shapedprofilebutalsoperiodic.Thevariationofparameterscharacterisingtheprofilewasconfinedtothedepthofthevalley(nochangeofperiodlengthswasperformed).Theinfluenceofinter-faceshapewithandwithoutoxidescaleonthestresslevelsandparticularlyontheirattenuationwithincreas-ingdistancefromtheinterfacewasthereforeonlypartiallyexamined.Ingeneral,thefindingsofw15xareinagreementwithourresults.Anumberofotherpublicationsalsodealwiththedevelopmentofstressesaftercooling,buttheylackdetailedinvestigationsontheinfluenceofroughness-relatedparametersonstressesw16–18x.References

w1xM.J.Stilger,N.M.Yanar,M.G.Topping,F.S.Pettit,G.H.

Meier,Thermalbarriercoatingsforthe21stcentury,Zeitschr.Metallk.90(1999)1069–1078.

w2xR.A.Miller,Currentstatusofthermalbarriercoatings—an

overview,Surf.Coat.Technol.30(1987)1–11.

w3xJ.Thornton,Thermalbarriercoatings,Mater.Forum22(1998)

159–181.w4xD.Stover,¨C.Funke,Directionsofdevelopmentsofthermal

barriercoatingsinenergyapplications,Mater.Process.Technol.92y93(1999)195–202.

w5xJ.T.deMasi,K.D.Sheffler,M.Ortiz,Thermalbarriercoating

lifepredictionmodeldevelopment,Phase1FinalReport,ContractNAS3-23944,NASACR182230,NASA,1989.

w6xS.M.Meier,D.M.Nilsey,K.D.Sheffler,Thermalbarrier

coatinglifepredictionmodeldevelopment,Phase2FinalReport,ContractNAS3-23944,NASACR189111,NASA,1991.

w7xR.Vaßen,G.Kerkhoff,D.Stover,¨Developmentofamicro-mechanicallifepredictionmodelforplasmasprayedthermal

barriercoatings,Mater.Sci.Eng.A303(2001)100–109.w8xG.Kerkhoff,ComparisonofExperimentallyObservedFatigue

BehaviourandCalculatedStressDistributionsinThermallyLoadedPlaneandCurved8YSZThermalBarrierCoatings,

PhDThesis,RuhrUniversitat,

¨Bochum,Germany,2000.w9xG.Kerkhoff,R.Vaßen,C.Funke,D.Stover,¨Finiteelement

analysisofthermalstressesinthermalbarriercoatingson

cylindricalsubstrates,in:Proceedingsofthe6thLiege

`Confer-ence,PartIII,MaterialsforAdvancedPowerEngineering,J.Lecomte-Beckers,F.Schubert,P.J.Ennis,(Eds.),Forschungs-zentrumJulich¨GmbH,Julich,¨Germany,1998,pp.1669–1678.

w10xJ.T.DeMasi-Marcin,K.D.Sheffler,S.Bose,J.Eng.GasTurbinesPower112(1990)521.

w11x

D.M.Nissey,J.ThermalSprayTechnol.6(1)(1997)91.w12xG.Qian,T.Nakamura,C.C.Berndt,S.H.Leigh,ActaMater.45(4)(1997)1767.

w13xC.H.Hsueh,E.R.Fuller,Analyticalmodellingofoxidethick-nesseffectsonresidualstressesinthermalbarriercoatings,ScriptaMater.42(2000)781–787.

w14xC.H.Hsueh,E.R.Fuller,Residualstressesinthermalbarriercoatings:effectofinterfaceasperitycurvatureyheightandoxidethickness,Mater.Sci.Eng.A283(2000)46–55.

w15x

M.-J.Pindera,J.Aboudi,S.M.Arnold,Theeffectofinterfaceroughnessandoxidefilmthicknessontheelasticresponseofthermalbarriercoatingstothermalcycling,Mater.Sci.Eng.A284(2000)158–175.

w16xA.M.Freborg,B.L.Ferguson,W.J.Brindley,G.J.Petrus,Modellingoxidationinducedstressesinthermalbarriercoat-ings,Mater.Sci.Eng.A245(1998)182–190.

w17xG.J.Petrus,B.L.Ferguson,Asoftwaretooltodesignthermalbarriercoatings:atechnicalnote,J.ThermalSprayTechnol.6w18x(G.C.1)(1997Chang,)29–34.

W.Phucharoen,Finiteelementthermalstresssolutionsforthermalbarriercoatings,Surf.Coat.Technol.32w19x

(E.P1987.Busso,)307–325.

J.Lin,S.Sakurai,M.Nakayama,Amechanisticstudyofoxidation-induceddegradationinaplasma-sprayedthermalbarriercoatingsystem.PartI:modelformulation,ActaMater.49(2001)1515–1528.

w20xM.Jinnestrand,S.Sjostrom,¨¨Investigationsby3DFEsimula-tionsofdelaminationcrackinitiationinTBCcausedby

aluminagrowth,Surf.Coat.Technol.135(2001)188–195.w21xABAQUS,User’smanual,Version5.8,Hibbit,Karlsson&Sorenson,Inc,1998.

w22xD.Basu,C.Funke,R.W.Steinbrech,EffectofheattreatmentonelasticpropertiesofseparatedTBCs,J.Mater.Res.14(12)w23x

(S.R.1999Choi,)4643–4650.

D.-M.Zhu,R.A.Miller,Deformationandstrengthbehaviorofplasma-sprayedZrO2–8wt.%Y2O3thermalbarriercoatingsinbiaxialflexureandtrans-thicknesstension,Ceram.Eng.Sci.Proc.21(4)(2000)653–661.

w24xM.Ahrens,R.Vaßen,mpenscherf,D.Stover,¨Sintering

andcreepprocessesinplasma-sprayedthermalBarrierCoat-ings,J.ThermalSpray,inpress.

w25x

R.Vaßen,G.Kerkhoff,M.Ahrens,D.Stover,¨Lifetime

predictionmodelforplasma-sprayedthermalbarriercoatingsbasedonamicromechanicalapproach,in:J.G.Heinrich,F.Aldinger(Eds.),CeramicMaterialsandComponentsforEngines,Wiley-VCH,Weinheim,2001,p.305ff.