Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/9626
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dc.contributor.advisor顏秀崗zh_TW
dc.contributor.advisorYEN S. K.en_US
dc.contributor.author許進添zh_TW
dc.contributor.authorHSU, CHIN-TIENen_US
dc.date2006zh_TW
dc.date.accessioned2014-06-06T06:43:34Z-
dc.date.available2014-06-06T06:43:34Z-
dc.identifier.urihttp://hdl.handle.net/11455/9626-
dc.description.abstract本研究以電解沉積法於IN617 超合金表面鍍上氧化釔(Y2O3)陶瓷塗層、氧化釔-氧化鋁(Y2O3/Al2O3))複合塗層,期提高基材之抗蝕性及抗高溫氧化能力。實驗結果顯示在-0.95 V ~ -2.5 V氫氧化釔之沉積反應為: 2(Y+3)(H2O)6 + 6e-®2Y(OH)3.3H2O + 3H2 藉由XRD, DSC ,TGA 進一步分析發現,熱處理過程中,於366℃吸附水與結晶水會完全失去。488℃則縮合成YOOH,最後於550℃轉化成Y2O3而且均勻附著在基材上。另一複合鍍層實驗結果發現熱處理過程中,於400℃吸附水與結晶水會完全失去,化學反應為: Y(OH)3•3H2O →Y(OH)3 + 3 H2O Al(OH)3•0.5H2O → Al(OH)3 + 0.5 H2O 800℃則縮合成YOOH及AlOOH,且於1000℃轉化成釔鋁石榴石(YAG)保護膜,其化學反應為: 3YOOH + 5AlOOH → Y3Al5O12 + 4H2O 再藉由sem觀察,相變化分析、高溫熱循環試驗、熱腐蝕試驗及電化學循環極化測試,此鍍膜均勻附著性佳。在常溫3.5% NaCl水溶液中、850℃ Na2SO4腐蝕環境中或1000℃高溫空氣中,氧化釔鍍層與氧化釔-氧化鋁複合塗層均比基材表現出較佳的抗蝕與抗高溫氧化能力。唯於鹽酸(HCl) 水溶液中,只有複合鍍層具有抵抗能力,因為氧化釔會溶於鹽酸(HCl)水溶液。zh_TW
dc.description.abstractThe mechanism of electrolytic yttrium hydroxide thin film deposition on IN617 superalloy in Y(NO3)3 aqueous solution were investigated. The cathodic polarization curve in Y(NO3)3 aqueous solution can be divided into two portions: 1. the reduction of H+ and O2, 2. the reduction of (Y+3)(H2O)6 i.e. 2(Y+3)(H2O)6 + 6e-2Y(OH)3.3H2O + 3H2 at -0.95 V ~ -2.5 V. it was found that the as-coated film was hydrated Y(OH)3.3H2O, dehydrated into Y(OH)3.H2O at 122℃, further dehydrated into Y(OH)3 at 366℃, condensed into YOOH at 480℃, and finally transformed into Y2O3 at 550℃. Also, a novel method of electrochemical synthesis of YAG (yttrium aluminum garnet) thin film coating on IN617 has been successfully developed. The coating film was composed of hydrated Y(OH)3•3H2O and Al(OH)3•0.5H2O, the physical adsorbed water evaporated between 25 and 103℃, dehydrated into Y(OH)3 and Al(OH)3 between 103 and 400℃, condensed into YOOH and AlOOH between 400 and 850℃, and finally transformed into single phase YAG (Y3Al5O12) between 850 and 1000℃ by the reaction, 3YOOH + 5AlOOH  Y3Al5O12 + 4H2O Thermal cycle tests, hot corrosion in Na2SO4, and corrosion in HCl aqueous solutions of the IN617 substrate, Y2O3 coated, Y2O3/Al2O3 double layers coated and YAG coated are further conducted to investigate the high temperature oxidation and corrosion. It was found that the Y2O3 coating and the composite coating could improve significantly the resistance of thermal cycle oxidation, hot corrosion in Na2SO4. The Y2O3 and Y2O3/Al2O3 composite coated specimens revealed only a small amount of weight variation because of the formation of protective films, such as Y2O3, Y2O3/Al2O3 and YAG. The composite coated specimen also revealed excellent corrosion resistance in HCl aqueous solution. However, the Y2O3 coated specimen revealed more weight loss than the uncoated in HCl aqueous solution, since the dissolution of Y2O3 coatings resulted in the exposure of the substrate.en_US
dc.description.tableofcontents摘要---------------------------------------------------------------------------------1 Abstract-----------------------------------------------------------------------------3 Figure Contents ------------------------------------------------------10 Table Contents------------------------------------------------------------------17 Chapter 1 Introduction----------------------------------------------------------18 1.1 Overview---------------------------------------------------------------------18 1.2 Motivation--------------------------------------------------------------------19 1.3 Ceramic coatings as materials of protective layers---------------------21 1.4 The yttrium oxide as protection layer------------------------------------21 1.5 Al2O3 / Y2O3 double-layer coatings as the high temperature resistance materials--------------------------------------------------------------------25 1.6 The artificial crystal-YAG-------------------------------------------------26 1.7 Objectives of the thesis----------------------------------------------------28 Chapter 2 Theory---------------------------------------------------------------29 2.1 Electrochemical aspects---------------------------------------------------29 2.1.1 Electrolytic deposition----------------------------------------------29 2.1.2 Electrochemical polarization -------------------------------------29 2.1.3 Electrochemical passivity-------------------------------------------37 2.1.4 Electrochemical deposition cell resistance------------------------38 2.2 The rules of Pauling and Baur---------------------------------------------40 2.3 The relative position of Y and O atoms in Y2O3------------------------41 2.4 The phase diagram of the system Y2O3-Al2O3 at high temperature---42 2.5 The relative position of Y, Al, and O atoms at YAG--------------------44 Chapter 3 Experimental procedures-------------------------------------------45 3.1 Electrolytic deposition Y2O3 coating on IN617 superalloy------------46 3.1.1 Specimen preparation------------------------------------------------46 3.1.2 Polarization tests-----------------------------------------------------46 3.1.3 Electrolytic deposition----------------------------------------------48 3.1.4 Heat treatment--------------------------------------------------------48 3.1.5 TGA and DSC---------------------------------------------------------48 3.1.6 SEM and XRD-------------------------------------------------------51 3.2 Electrolytic Al2O3/Y2O3 Double-Layer Coating on IN617-----------54 3.2.1 Sample preparation---------------------------------------------------54 3.2.2 Electrolytic deposition-----------------------------------------------55 3.2.3 Cathodic polarization------------------------------------------------55 3.2.4 Heat treatment-----------------------------------------------------56 3.2.5 XRD and SEM----------------------------------------------------56 3.2.6 TGA----------------------------------------------------------------57 3.2.7 Aqueous corrosion tests---------------------------------------57 3.2.8 Cyclic thermal tests------------------------------------------------57 3.3 Electrochemical synthesis of thin film YAG on Inconel substrate --58 3.3.1 Cathodic polarization tests and deposition-----------------------58 3.3.2 Thermogravimetry analysis (TGA) ----------------------------59 3.3.3 X-ray diffraction (XRD) and surface morphology analysis---59 3.3.4 Fourier transform infrared (FTIR) analysis-------------------60 3.4 High Temperature Oxidation and Corrosion of Y2O3 coated and Y2O3-Al2O3 composite coated IN617 superalloy-----------------------61 3.4.1 Sample preparation------------------------------------------------61 3.4.2 Electrolytic deposition and annealing-------------------------61 3.4.3 Thermal gravitational analysis (TGA) -------------------------62 3.4.4 Aqueous corrosion tests------------------------------------------63 3.4.5 Cyclic thermal tests-------------------------------------------------63 3.4.6 The immersion tests-----------------------------------------------63 3.4.7 Hot corrosion tests--------------------------------------------------64 3.4.8 XRD and SEM-----------------------------------------------------64 Chapter 4 Results and discussion---------------------------------------------65 4.1 Electrolytic deposition Y2O3 coating on IN617 superalloy-----------65 4.1.1 Cathodic reactions-------------------------------------------------65 4.1.2 TGA/DSC and XRD analysis--------------------------------------68 4.1.3 SEM observations and EDS mapping-------------------------73 4.1.4 High temperature oxidation-------------------------------------75 4.2 Electrolytic Al2O3/Y2O3 Double-Layer Coatings on IN617 ---------76 4.2.1 Cathodic reactions--------------------------------------------76 4.2.2 SEM observation and EDS mapping-------------------------79 4.2.3 TGA and XRD analysis----------------------------------------82 4.2.4 Cyclic polarization--------------------------------------------86 4.3 Electrochemical synthesis of thin film YAG on Inconel substrate---------------------------------------------------------------------88 4.3.1 Cathodic reactions---------------------------------------------------88 4.3.2 Phase transformations-----------------------------------------------91 4.3.3 Morphology observations---------------------------------------96 4.4 High Temperature Oxidation and Corrosion of Y2O3 coated and Y2O3-Al2O3 composite coated IN617 superalloy-----------------------97 4.4.1 Aqueous corrosion---------------------------------------------------97 4.4.2 Cyclic thermal test--------------------------------------------------99 4.4.3 Hot corrosion-------------------------------------------------------104 4.4.4 Immersion test in 0.5 M HCl-------------------------------------106 Chapter 5 Summary and Conclusion--------------------------------------------------------108 References ----------------------------------------------------------------------112zh_TW
dc.language.isoen_USzh_TW
dc.publisher材料工程學系zh_TW
dc.subjectElectrolytic depositionen_US
dc.subject電解沉積zh_TW
dc.subjectY2O3en_US
dc.subjectYAGen_US
dc.subjectHot corrosionen_US
dc.subjectHigh temperature oxidation.en_US
dc.subject氧化釔zh_TW
dc.subject釔鋁石榴石zh_TW
dc.subject熱腐蝕zh_TW
dc.subject高溫氧化zh_TW
dc.title電解沉積Y2O3與Al2O3鍍層於IN617超合金之研究zh_TW
dc.titleElectrolytic Y2O3 and Al2O3 Coatings on IN617 Superalloyen_US
dc.typeThesis and Dissertationzh_TW
item.fulltextno fulltext-
item.languageiso639-1en_US-
item.openairetypeThesis and Dissertation-
item.cerifentitytypePublications-
item.openairecristypehttp://purl.org/coar/resource_type/c_18cf-
item.grantfulltextnone-
Appears in Collections:材料科學與工程學系
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