臺灣博碩士論文加值系統

片狀氧化鋁因為具有高熔點、絕緣性、耐磨性、機械強度以及優異的化學穩定性。且其具有二維的外型，在工業界上已被廣泛的添加到其他材料中當作補強物，形成多功能的複合材料。本研究藉由添加不同莫耳比例的硫酸鉀(K2SO4)於含5mol%Fe3+離子的水鋁石(boehmite)中，經由1000oC熱處理後，可獲得六角片狀α-Al2O3單晶粉末，其長度約為200nm。若再共添加1mol% Ti4+離子則可增加其形狀異方性，片狀晶粒直徑可增加到400nm。隨著添加硫酸鉀莫耳比例的增加，其相轉換路徑由未添加硫酸鉀前的γ→θ→α-Al2O3，改變成γ→α-Al2O3，且其抑制γ-Al2O3晶粒成長的效果也隨之提昇；當硫酸鉀的添加量和boehmite的莫耳比是4:1時，其α-Al2O3的相轉換量只達到83%，顯示硫酸鉀可抑制γ-Al2O3之晶粒成長使其無法達到α-Al2O3相轉換的臨界粒徑。又由添加1mol% Ti4+離子之樣品中發現Ti4+離子傾向偏析在α-Al2O3的(004)面上，使得α-Al2O3產生異向性的成長，進而增加片狀氧化鋁的異方性(anisotropy)。研究中藉由DTA、XRD、TEM、EDS來分析添加硫酸鉀及Ti4+離子對Al2O3相轉換及其外型上的影響，結果發現添加共添加硫酸鉀、Fe3+離子及Ti4+離子不但可以提前γ→α-Al2O3之相轉換，也可以使α-氧化鋁之外型由原本的蠕蟲狀改變成薄片狀；而片狀氧化鋁的成長機構主要是由針狀α-Al2O3以硫酸鉀為模板，藉由粒子的重排而生成片狀氧化鋁。

Alumina exhibits superior properties, such as high melting point, wear resistance, thermal as well as electrical insulation, perfect mechanical strength and chemical stability. Therefore, flaky alumina powders are often used as reinforcements in various materials to form multi-functional composites because of its two-dimensional shape. In this study different amount of potassium sulfate were added into boehmite with 5mol%Fe3+ ions to prepare a single-crystal α- Al2O3 hexagonal flake with a diameter of about 200 nm after calcining at 1000℃. Codoping 1mol% Ti4+ ions could promote the shape anisotropy and the diameter growth to about 400 nm. Without the addition of potassium sulfate, transformation of boehmite to α-Al2O3 is via the γ→θ→δ→α-Al2O3 path. However the transformation path was changed to γ→α-Al2O3 with the addition of potassium sulfate. Only achieved 83% of α-Al2O3 phase transformation was obtained as the molar ratio of potassium sulfate to boehmite achieved four. Potassium sulfate suppressed γ-Al2O3 coarsening which hence inhibited γ→α-Al2O3 phase transformation and inhibited the γ-Al2O3 to reach the critical nuclei size of α-Al2O3. In addition, it was found that Ti4+ ions had a strong tendency to segregate onto the (004) phase of α-Al2O3,which enhanced α-Al2O3 anisotropic growth and increased the shape anisotropy of flaky α-Al2O3. The effect of the addition of potassium sulfate and Ti4+ ions on the Al2O3 phase and morphology were investigated using differential thermal analysis (DTA), X-ray diffraction (XRD), transmission electron microscopy (TEM), Energy Dispersive Spectrometer (EDS). It was found that the addition of potassium sulfate, Fe3+ ions and Ti4+ ions could effectively prevent from the occurrence of α-Al2O3 vermicular growth and promoted phase transformation of intermediate γ-Al2O3 to α-Al2O3, which helped the formation of flaky single-crystal α-Al2O3 growth mechanism of flaky α-Al2O3 was via the oriented attachment of needle-like α-Al2O3 using of potassium sulfate as a template.

摘要 I
Abstract III
目錄 V
致謝 Ⅴ
表目錄 VII
圖目錄 VII
第一章 緒論 1
1-1前言 1
1-2研究目的 2
第二章 理論基礎與前人研究 3
2-1水鋁石及過渡相氧化鋁之結晶相、相轉換及微結構的變化 3
2-1-1 boehmite→α-Al2O3的相轉換過程 3
2-1-2 γ→α、θ→α相轉換過程的觀察 4
2-2添加劑對於相轉換的影響 7
2-3晶體產生異方性成長的原理 10
2-3-1奈米粒子粗化的機制 10
2-3-2晶體產生異方性成長的原理 11
2-4片狀α-Al2O3生成方式 13
第三章 實驗方法及步驟 27
3-1起始原料的製備 27
3-2粉末的製備 27
3-2-1起始物的定量 27
3-2-2實驗流程 28
3-3粉末性質測定 29
3-3-1熱差及熱重分析 29
3-3-2 X光繞射分析儀 29
3-3-2-1相轉換量的測定 29
3-3-2-2異方性成長指數的測定 30
3-3-3顯微結構分析 30
第四章 結果與討論 36
4-1添加異質離子對boehmite熱行為及相轉換的影響 36
4-1-1添加Fe3+離子對於boehmite熱行為及相轉換的影響 36
4-1-2共添加Fe3+、Ti4+對於boehmite的熱行為及相轉換的影響 37
4-1-3硫酸鉀對於含(Fe3+、Ti4+)boehmite熱行為及相轉換的影響 38
4-2添加硫酸鉀對α-Al2O3含量及異方性(Anisotropy)的影響 40
4-2-1添加硫酸鉀對於α-Al2O3含量的影響 40
4-2-2添加硫酸鉀對異方性(Anisotropy)的影響 41
4-3片狀氧化鋁的成長機構 43
4-4添加Ti4+離子對於異方性成長的影響 45
4-5綜合討論 47
4-6與前人文獻的比較 47
第五章 結論 63
參考文獻 64
Appendix 70
自述 73

1.K. H. Heussner and N. Claussen, “Yttria- and Ceria-Stabilized Tetragonal Zirconia Polycrystals (Y-TZP, Ce-TZP) Reinforced with Al2O3 Platelets,” J. Euro. Ceram. Ceram. Soc., 5, 193-200 (1989).
2.H.C. Yuen, W.B. Lee, and B. Ralph, “Hot-Roll Bonding of Aluminum-Matrix Composites with Different Volume Fractions of Alumina,” J. Mater. Sci., 30 [4] 843-848 (1995).
3.J. Block and J.W.K. Lau, “Thermally Conductive Elastomer Containing Alumina Platelets,” US patent 5137959.
4.N. Katuhisa, “Flaky Aluminum Oxide and Pearlescent Pigment and Production thereof,” EP Patent, 0763573A3.
5.C. A. Shaklee and G. L. Messing, “Growth of α-Al2O3 Platelets in the HF-γ-Al2O3 System,” J. Am. Ceram. Soc., 77 [11] 2977-84 (1994).
6.S. Hashimoto and A. Yamaguchi, “Synthesis of α-Al2O3 Platelets Using Sodium Sulfate Flux,” J. Mater. Res., 14 [12] 4667-72 (1999).
7.S. Hashimoto and A. Yamaguchi, “Formation of Porous Aggregations Composed of Al2O3 Platelets Using Potassium Sulfate Flux,” J. Euro. Ceram. Soc., 19, 335-39 (1999).
8.N. S. Bell and S.B. Cho, J.H. Adair, “Size Control of α-Alumina Particles Synthesized in 1,4-Butanediol Solution by α-Alumina and α-Hematite Seeding,” J. Am. Ceram. Soc., 81 [6] 1411-20 (1998).
9.M. Wei and K.L. Choy, “Novel Synthesis of α-Alumina Hexagonal Nanoplates Using Electrostatic Spray Assisted Chemical Vapor Deposition,” Nanotechnology, 17, 181-84 (2006).
10.Y. X. Li, W. F. Chen, X. Z. Zhou, Z.Y. Gu, and C. M. Chen, “Synthesis of CeO2 Nanoparticles by Mechanochemical Processing and the Inhibiting Action of NaCl on Particle Agglomeration,” Mater. Lett., 59, 48-52 (2005).
11.W. O. Milligan and J. L. McAtee, “Crystal Structure of γ-AlOOH and ScOOH,” J. Phy. Chem., 60, 273-277 (1956).
12.F. J. Ewing, “The Crystal Structure of Lepidocrocite,” J. Chem. Phys., 3, 420-454 (1935).
13.K. Wefer and C. Misra, “Oxides and Hydroxides of Aluminum,” Alcoa Technical Paper NO.19, Aloca Laboratories, Pittsburgh, PA1987
14.I. Levin and D. Brandon, “Metastable Alumina Polymorphs: Crystal Structures and Transition Sequences.” J. Am. Ceram. Soc., 81 [8] 1995–2012 (1998).
15.G. Yamaguchi and H. Yanagida, “Thermal Effects on the Lattices of η and γ-Aluminum Oxide,” Bull. Chem. Soc. Jap., 37, 1229-31 (1964)
16.B. C. Lippens and J. H. de Boer, “Study of Phase Transformations during Calcinations of aluminum Hydroxides by Selected Area Electron Diffraction,” Acta Cryst., 17, 1312-1321 (1964).
17.I. M. Low and R. Mcpherson, “Crystallization of Gel-Derived Alumina and Alumina-Zirconia Ceramics,” J. Mater. Sci., 24, 892-898 (1989).
18.J. A. Kohn, G. Katz, and J. D. Broder, “β-Ga2O3 and Its Alumina Isomorphs’θ-Al2O3,” Am. Miner., 42, 398-408 (1957).
19.L. D. Hart, Alumina Chemical：Science and Technology Handbook, Am. Ceram. Soc. Inc., Westerville, Ohio, 1990.
20.T. C. Chou and T. G. Nieh, “Interface-controlled Phase Transformation and Abnormal Grain Growth of α-Al2O3 in Thin γ-Alumina,” Thin Solid Films, 221, 89-97 (1992).
21.D. R. Clarke, “Epitaxial Phase Transformations in Aluminum Oxide,” Phys. Stat. Sol., (a) 166 -183 (1998).
22.R. B. Bagwell and G. L. Messing, “Effect of Seeding and Water Vapor on the Nucleation and Growth of α- Al2O3 from γ-Al2O3,” J. Am. Ceram. Soc., 82 [4] 825-832 (1999).
23.J. R. Wynnyckyj and C. G. Morris, “A Shear-Type Allotropic Transformation in Alumina,” Metal. Trans. B., 16B, 345-53 (1985).
24.K. Wefer and C. Misra, “Oxides and Hydroxides of Aluminum,” Aloca Technical Paper No. 19, Aloca Laboratories, Pittsburgh, PA, 1987.
25.J. L. McArdle, “Seeding with Ferric-Oxide for Enhance Transformation and Microstructure Develop in Boehmite-Derived Alumina,” Ph. D. Thesis, The Pennsylvania State University.
26.G. C. Bye and G. T. Simpkin, “Influence of Cr and Fe Formation of α-Al2O3 from γ-Al2O3,” J. Am. Ceram. Soc., 57 [8] 367-71 (1974).
27.J. L. McArdle and G. L. Messing, “Transformation, Microstructure Development, and Densification in α-Fe2O3-seeded Boehmite-Derived Alumina,” J. Am. Ceram. Soc., 76 [1] 214-22 (1993).
28.M. Nofz and G. Scholz, “Fe3+-assisted Formation of α-Al2O3, Starting from Sol–Gel Precursors,” J. Solid State Chem. 179, 652–664 (2006).
29.Phase Equilibrium Diagrams for Ceramists, Vol.Ⅰ, Am. Ceram. Soc., Ohio, USA, 2093-2096.
30.J. L. McArdle and G. L. Messing, “Seeding with γ-Al2O3 for Transformation and Microstructure Control in Boehmite-Derived α-Alumina,” J. Am. Ceram. Soc., 69 [5] 98–101 (1986).
31.R. Venkataraman, P. Singh and R. Krishnamurthy, “Enhance α Phase Stability During Plasma Spraying of Alumina-13mol% Titania,” J. Am. Ceram. Soc., 89 [2] 734-736 (2006).
32.K. Okada, A. Hattori, Y. Kameshima, A. Yasumori, and R. N. Das, “Effect of Monovalent Cation Additives on the γ-Al2O3 to α-Al2O3 Phase Transition,” J. Am. Ceram. Soc., 83 [5] 1233–36 (2000).
33.A. G. Alejandre, M. G. Cruz, and M. Trombetta, “Characterization of Alumina-Titania Mixed Oxide Supports PartⅡ：Al2O3-Based Supports,” Micro. Meso. Mater. 23, 265-275 (1998).
34.W. D. Kingery, H. K. Bowen, and D. R. Uhlmann, Introduction to
Ceramics, John Wiley & Sons, New York, 2nd Ed., 1976.
35.H. Zhang and J. F. Banfield, “New Kinetic Model for the Nanocrystalline Anatase-to-Rutile Transformation Revealing Rate Depending on Number of Particles,” Am. Miner., 84, 528-535 (1999).
36.A. Yasuo, Chemistry of Powder Production, Chapman & Hall, New York, 1996.
37.C. Klein and C. S. Hurlbut, Jr., Manual of Mineralogy, Wiley, New York, 1993.
38.A. Kebbede and G. L. Messing, “Grain Boundaries in Titania-Doped α-Alumina with Anisotropic Microstructure,” J. Am. Ceram. Soc., 80 (11) 2814-20 (1997).
39.D. S. Horn and G. L. Messing, “Anisotropic Grain Growth in TiO2-Doped Alumina,” Mater. Sci. Eng. A 195 169-178 (1995).
40.王孝平 , 賃敦敏 , 廖運文 , 肖定全 “無鉛壓電陶瓷粉體的製備和晶粒定向生長技術,” << 材料導報 >> 10期16-18 2005年。。
41.M. M. Seabaugh and G. L. Messing, “Texture Development and Microstructure Evolution in Liquid-Phase-Sintered α-Alumina Ceramics Prepared by Templated Grain Growth,” J. Am. Ceram. Soc., 83 [12] 3109–16 (2000).
42.A. S. Myerson, Handbook of Industrial Crystallization, Butterworth-
Heinemann, Boston, 1993.
43.Wu Y. Q., Zhang Y. F., Huang X. X., and Guo J. K., “Preparation of Platelike Nano Alpha Alumina Particles,” Ceram. Inter. 27, 265~268 (2001).
44.J. S. Robinson, L. M. Cukrov, D. A. Lee, and P. G. McCormick, World Patent 2004/060804.
45.B. Y. Yu and W. C. Wei, “Growth of Tabular α-Al2O3 Grain on Alumina Substrate,” J. Am. Ceram. Soc., 91 [2] 595–598 (2008).
46.黃俊琪，添加鐵離子對氧化鋁θ到α相轉換之影響，國立成功大學資源工程學系碩士論文。
47.溫惠玲，由beohmite製得之氧化鋁微粉之θ→α-Al2O3相轉換，國立成功大學資源工程研究所博士論文。
48.R. F. Hill and R. Danzer, “Synthesis of Aluminum Oxide Platelet,” J. Am. Ceram. 84 [3] 514-20 (2001).
49.H. C. Park, S. W. Kim, S. G. Lee, J. K. Kim, S. S. Hong, G. D. Lee, and S. S. Park, “Synthesis of α-Alumina Platelets Using Flux Method in 2.45 GHz Microwave Filed,” Mater. Sci. and Eng. A363, 330-334 (2003).
50.Y. Q. Wu, Y. F. Zhang, X. X. Huang, and J. K. Guo, “Preparation of Platelike Nano Alpha Alumina Particles.” Ceram. Inter. 27, 265-268 (2001).
51.Y. Wu, K. L. Chyo and L. L. Hench, “Preparation of α-Alumina Platelets by Laser Scanning,” J. Am. Soc. 87 [8] 1606-608 (2004).
52.K. A. Sionsen and M. Zaharescu, “A New Differential Thermal Analysis Method,” M. Therm. Anal. 15, 25-35 (1979).
53.S. L. K. Sylvie, L. Corinne, C. Clande and H. Frederic, “Titanium Effect on Phase Transformation and Sintering Behavior of Transition Alumina,” J. Euro. Ceram. Soc., 26, 2219–2230 (2006).
54.王士碩，利用化學共沉法製作二氧化鈦變阻器之研究，國立成功大學資源工程學系碩士論文。
55.M. M. Seabaugh, I. H. Kerscht and G. L. Messing, “Texture Development by Templated Grain Growth in Liquid-Phase-Sintered α-Alumina,” J. Am. Ceram. Soc., 80 [5] 1181–88 (1997).
56.A. Putnis and J. D. C. McConnell, Principles of Mineral Behavior, Elsevier, New York, 1980.