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http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/38284Full metadata record
| ???org.dspace.app.webui.jsptag.ItemTag.dcfield??? | Value | Language |
|---|---|---|
| dc.contributor.advisor | 段維新(Wei-Hsing Tuan) | |
| dc.contributor.author | Chang-Ju Ho | en |
| dc.contributor.author | 何昌儒 | zh_TW |
| dc.date.accessioned | 2021-06-13T16:29:29Z | - |
| dc.date.available | 2011-07-26 | |
| dc.date.copyright | 2011-07-26 | |
| dc.date.issued | 2011 | |
| dc.date.submitted | 2011-07-19 | |
| dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/38284 | - |
| dc.description.abstract | 氧化鋯(ZrO2)陶瓷由於其結合高強度、高韌性、高離子傳導率及低熱導率的性質，已經被廣泛地應用在包括結構、能源及生醫方面。在一些應用中; 如固態氧化物燃料電池(SOFC)及熱阻絕鍍膜(TBC)，氧化鋯暴露在高溫還原的環境中。因此，研究氧化鋯在此嚴苛環境中的穩定性對其效能的影響有其重要性。在本研究中，3 mol%氧化釔安定氧化鋯(YSZ)放置在石墨粉體床中並在溫度1400℃至1600℃ 進行燒結。瑝燒結溫度高於1500℃，在試樣表面可觀察到相轉變及異常晶粒成長。在試樣表面的正方相(t,正方性=1.016)相轉變到第二正方相(t’,正方性=1.012)，表面異常晶粒成長伴隨此相轉移出現。瑝試樣在1600℃燒結後，其表面晶粒粒徑達到16 μm，比試樣內部晶粒粒徑(1 μm)龐大許多。瑝添加0.6 vol%的鎳，此表面異常晶粒粒徑降低至7 μm，但是第二正方相依然存在。
另外，複合材料經常被設計來作為加強母相材料的本質性質或加入額外的功能。在本研究中，首先對YSZ/NiO 系統之機械性質進行研究，相較於純氧化鋯，其強度及破壞韌性都獲得提升。強度的提升源於氧化鎳幫助燒結，破壞韌性的提升源於氧化鎳幫助晶粒成長以及相穩定。接著使用兩種燒結方式製備YSZ/Ni 試樣: 1.傳統無壓燒結 2.內部還原法。藉由內部還原法製程能夠確保複合材料的緻密化，將燒結緻密的YSZ/NiO 固溶物，放到還原環境中進行熱處理以還原出金屬鎳。此經由內部還原法製備的複合材料之鎳含量為0.06 vol%。此YSZ/Ni 複合材料依然具有如同YSZ/NiO 試樣的高強度性質(高於1.5GPa)。其破壞韌性則能得到進一步提升(高於8 MPa*m0.5)。另外，鎳的鐵磁性亦呈現於複合材料中，有利於感測方面的應用設計。 | zh_TW |
| dc.description.provenance | Made available in DSpace on 2021-06-13T16:29:29Z (GMT). No. of bitstreams: 1 ntu-100-D94527007-1.pdf: 10519357 bytes, checksum: 8b136559caae716facfbbabce4abef00 (MD5) Previous issue date: 2011 | en |
| dc.description.tableofcontents | Chapter 1 Introduction 1
Chapter 2 Literature Survey 3 2-1 Basic of Zirconia 3 2-1-1 Phases of zirconia 3 2-1-2 Transformation toughening 3 2-1-3 ZrO2-Y2O3 (YSZ) system 4 2-1-4 Low temperature degradation (LTD) 6 2-2 Influence of reducing environment on ZrO2 13 2-3 t’ phase of ZrO2 and TBC 14 2-3-1 t’ phase 14 2-3-2 Thermal barrier coating (TBC) 16 2-4 Grain Growth of ZrO2 22 2-5 Mechanical Properties of YSZ 26 2-5-1 Fracture toughness 26 2-5-2 Strength 27 2-6 YSZ Based Composites 30 2-6-1 Fracture toughness 30 2-6-2 Strength 31 2-6-3 Magnetic properties 32 2-7 Internal Reduction Sintering 35 Chapter 3 Experimental Procedures 36 3-1 Preparation of Specimens 36 3-1-1 Materials 36 3-1-2 Ni-coated YSZ powder 36 3-1-3 NiO/YSZ powder mixture 37 3-1-4 Sintering 37 3-2 Characterization of Sintered Specimens 41 3-2-1 Phase identification by X-ray diffraction 41 3-2-2 Phase identification by Raman shift 41 3-2-3 Phase identification after ageing 42 3-2-4 Density measurement 42 3-2-5 Microstructural observation 42 3-2-6 Electron probe microanalyzer (EPMA) 43 3-3 Thermal Mechanical Analysis (TMA) 43 3-4 Mechanical Properties 44 3-4-1 Flexural strength and surface residual stress 44 3-4-2 Fracture toughness and hardness 45 3-5 Magnetic Property. 45 Chapter 4 Results 46 4-1 Appearance 46 4-2 Densification 47 4-2-1 YSZ and YSZ/Ni pressureless sintered in CO 47 4-2-2 YSZ/NiO and internal reduced YSZ/Ni 47 4-3 Microstructural Observation 51 4-3-1 YSZ and YSZ/Ni sintered in CO 51 4-3-2 YSZ/NiO and internal reduced YSZ/Ni 64 4-4 Phase Identification 69 4-4-1 YSZ and YSZ/Ni sintered in CO 69 4-4-2 YSZ/NiO and internal reduced YSZ/Ni 71 4-5 Yttria Distribution 85 4-6 Mechanical Properties 87 4-6-1 YSZ sintered in CO 87 4-6-2 YSZ/NiO and internal reduced YSZ/Ni 91 4-7 Magnetic property 94 Chapter 5 Discussion 97 5-1 Phase Stability and Microstructural Evolution of YSZ Specimens Sintered in a Highly Reducing Atmosphere 97 5-1-1 Phase transition 97 5-1-2 Grain growth behavior on surface 100 5-2 Enhanced densification by NiO and Ni addition 106 5-2-1 Enhanced densification by NiO solid solution 106 5-2-2 Enhanced densification in YSZ/Ni 109 5-3 Effect of an extremely small amount of NiO solid solution on the mechanical properties of YSZ 111 5-3-1 Toughening 111 5-3-2 Strengthening 122 5-4 YSZ/Ni composites 133 5-4-1 Influence of Ni particle on the microstructure of YSZ 133 5-4-2 Mechanical Properties 140 5-4-3 Magnetic properties 143 Chapter 6 Conclusions 146 Chapter 7 Future Work 148 Reference 150 | |
| dc.language.iso | en | |
| dc.title | 高度還原環境及微量添加鎳對釔安定氧化鋯之相穩定、微結構變化及機械性質之影響 | zh_TW |
| dc.title | Effect of Highly Reducing Environment and a Small Amount of Nickel Addition on the Phase Stability, Microstructural Evolution and Mechanical Properties of Yttria-Stabilized Zirconia | en |
| dc.type | Thesis | |
| dc.date.schoolyear | 99-2 | |
| dc.description.degree | 博士 | |
| dc.contributor.oralexamcommittee | 周振嘉,陳錦毅,謝宗霖,郭錦龍 | |
| dc.subject.keyword | 氧化鋯,還原環境,異常晶粒成長,鎳,氧化鎳,內部還原,破壞韌性,強度,磁性, | zh_TW |
| dc.subject.keyword | Zirconia,Reducing environment,t’ phase,Abnormal grain growth,Ni,NiO,Internal reduction,Fracture toughness,Strength,magnetic, | en |
| dc.relation.page | 169 | |
| dc.rights.note | 有償授權 | |
| dc.date.accepted | 2011-07-19 | |
| dc.contributor.author-college | 工學院 | zh_TW |
| dc.contributor.author-dept | 材料科學與工程學研究所 | zh_TW |
| dc.date.embargo-terms | 2300-01-01 | |
| dc.date.embargo-lift | 2300-01-01 | - |
| Appears in Collections: | 材料科學與工程學系 | |
Files in This Item:
| File | Size | Format | |
|---|---|---|---|
| ntu-100-1.pdf Restricted Access | 10.27 MB | Adobe PDF |
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