|
|
|
| STUDIES OF MICROSTRUCTURE AND PHASE OF EB-PVDTBCs EXPOSED TO ELEVATED TEMPERATURES |
| Meiheng Li;Xiaofeng Sun;Shengkai Gong;Zhongyuan Zhang;Hengrong Guan;Wangyu Hu;Zhuangqi Hu |
| 中国科学院金属研究所 |
|
|
|
|
Abstract A NiCrAlY bond coat had been deposited on a Ni- base single crystal superalloy by magnetron sputtering,and then a top coat (7 ma ss%Y2O3-ZrO2) had been deposited by electron beam-physical vapor depositio n (EB-PVD).The phase transformation of ceramic top coat was investigated and the surface morphology change of the samples was observed.It was found that the ZrO 2-7 mass% Y2O3 ceramic top coat deposited by EB-PVD showed columnar grain s which formed dense clusters and the surface was relatively dense.However there were gaps or holes among grain clusters,which allowed the lateral expansion and contraction of the ceramic columnar grains and allowed free expansion of the su bstrate over a relatively large range.After exposure to elevated temperatures,th e gaps among columnar grain clusters became larger.The relatively large gaps int erconnected into one another and formed microcracks.With thermal cycling going o n,the microcracks extended across and through the top coat.Also the Y2O3 con tent in nonequilibrium tetragonal phase decreased gradually,and the nonequilibri um tetragonal phase decomposed to equilibrium tetragonal and cubic phases.After 300 thermal cycles at 1050℃,small amount of monoclinic phase was formed from th e decomposition of the tetragonal phases.
|
|
Received: 03 December 2001
|
|
|
|
Corresponding Authors:
Meiheng Li
|
[1]MillerRA .Currentstatusofthermalbarriercoatings-anoverview[J].Sur.Coat.Technol.,1987,30:1-11
[2]MillerRA .Thermalbarriercoatingsforaircraftengines:historyanddirections[J].J.ThermalSprayTechnol.,1997,6(1):35-42
[3]JamesAS ,MatthewsA .DevelopmentsinR .F .Plasma-assistedphysicalvapordepositionpartiallyyttria-stabilizedzirconiathermalbarriercoatings[J].Surf.Coat.Technol.,1990,43/44:436-445
[4]LiMH ,ZhangZY ,SunXF ,HuWY ,GuanHR .InvestigationofmorphologyandphasestructurefeatureofTBC[J].MaterialsRe view,2001,15(1):71-73(李美女亘,张重远,孙晓峰,胡望宇,管恒荣.一种热障涂层的形貌和相结构特征研究[J].材料导报,2001;15(1):71-73)
[5]RigneyDV ,ViguieR ,WortmannDJ ,ShellyDW .PVDthermalbarriercoatingapplicationsandprocessdevelopmentforaircraften gines[J].J.ThermalSprayTechnol.,1997,6(2):167-175
[6]BennettA .Propertiesofthermalbarriercoatings[J].Mater.Sci.Technol.,1986,2(3):257-261
[7]MillerRA .Phasestabilityinplasmasprayedpartiallystabilizedzir conia-yttria[J].ScienceandTechnologyofZirconia,1981,3:241-253
[8]HeuerAH ,ChaimR ,LanteriV .ScienceandtechnologyofzirconiaⅢ[A].in:S .Somiya(Eds.),AdvancesinCeramics[C],Vol.24A ,AmericanCeramicSociety,Westerville,OH ,1988,3
[9]ScottHG .Phaserelationshipinzirconia-yttriasystem[J].J .Mater.Sci.,1975,10:1527-1535
[10]BandonRJ ,TaylorR .Phasestabilityofzirconia-basedthermalbarriercoatings.PartI .zirconia-yttriaalloys[J].Sur.Coat.Technol.,1991,46:75-90
[11]SheuTS ,TienTY ,ChenIW .Cubic-to-tetragonal(t′)trans formationinzirconia-containingsystems[J].J .Am.Ceram.Soc.,1992,75:1108-1116
[12]GuptaKT ,BechtoldJH ,KuznickiRC ,CadoffLH ,RossingBR .Stabilizationoftetragonalphaseinpolycrystallinezirconia[J].J .Mater.Sci.,1977,12:2421-2426
[13]VanValzahJR ,EatonHE .Coolingrateeffectsonthetetragonaltomonoclinicphasetransformationinagedplasma-sprayedyttriapartiallystabilizedzirconia[J].Sur.Coat.Technol.,1991,46:289-300
[14]LangeFF .Transformationtoughening.Part3experimentalobser vationintheZrO2-Y2O3 system[J].J.Mater.Sci.,1982,17:240-246
[15]MatsuiM ,SomaT ,OdaI.Stress-inducedtransformationandplasticdeformationforYO -containingtetragonalzirconiapoly crystals[J].Adv.Ceram.,1984,12:198-202 |
| No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|
