臺灣博碩士論文加值系統

本研究主要探討FeCoNiCrAl0.5塊狀高熵合金之環境腐蝕行為。將高週波熔煉法熔鑄之FeCoNiCrAl0.5五元高熵合金施以不同溫度時效熱處理，藉以探討於不同水溶液環境下之腐蝕行為及微結構觀察。將3.5 wt% NaCl、1N NaOH和1N H2SO4水溶液之實驗結果，與304L不�袗�極化曲線比較；於3.5 wt% NaCl 水溶液之極化數據比較中，304L不�袗�得到最低之腐蝕速率、FeCoNiCrAl0.5高熵合金具有最高之腐蝕速率；NaOH水溶液之極化數據比較中，304L不�袗�得到最低之腐蝕速率、FeCoNiCrAl0.5高熵合金具有最高之腐蝕速率；於H2SO4水溶液之極化數據比較中，304L不�袗�得到最高之腐蝕速率、FeCoNiCrAl0.5高熵合金得到最低之腐蝕速率，其中又以FeCoNiCrAl0.5高熵合金經由3.5 wt% NaCl 水溶液之FeCoNiCrAl 0.5塊狀高熵合金具有較差之抗蝕性，研判為FeCoNiCrAl 0.5高熵合金中含富Cr相形成，造成水溶液中氯離子易對Cr相攻擊反而造成腐蝕速率加快，抗蝕性變差。隨著熱處理溫度上升，FeCoNiCrAl0.5高熵合金的硬度變高。

The corrosion behavior of FeCoNiCrAl0.5 bulky high entropy alloy was studied. The homogenization treatment of the as-cast alloy specimen was processed. After water quenching serial heat-treatment processes were carried out. The corrosion properties, mechanical properties and microstructures of the specimens had been evaluated after the immersion tests with the NaCl, NaOH and H2SO4 solutions, respectively. The alloy has higher corrosion rate in 3.5 wt% NaCl aqueous solutions due to significant segregation of Cr-riched phase. Because of the active sensitivity zone of appreciable potential difference the alloy was preferentially attacked along the Cr-riched phase. The alloy exhibits excellent hardness after the immersion tests in NaOH and H2SO4 solution.

摘　　要 I
Abstract II
致 謝 II
目　　錄 II
圖 目 錄 V
表 目 錄 VIII
第1章 前言 1
第2章 文獻回顧 3
2.1 高熵合金的發展回顧 3
2.2 高熵合金的定義 4
2.3 高熵合金的研究 5
2.3.1 高熵合金的特性 5
2.3.2 高熵合金的應用 8
2.3.3 等莫耳多元高熵合金微結構 9
2.4 材料腐蝕 10
2.4.1 腐蝕之發生原因 10
2.4.2 腐蝕之型態 11
2.4.3 電化學極化法 13
2.4.4 腐蝕速率 17
2.4.5 鈍化與鈍化膜 18
第3章 實驗方法 19
3.1 基材製備 21
3.2 時效熱處理 21
3.3 試片研磨 21
3.4 材料顯微組織觀察及成份分析 22
3.5 X光繞射分析 22
3.6 電化學實驗 23
3.6.1 恆電位儀實驗設備及裝置 23
3.6.2 動電位極化曲線量測 23
3.7 微硬度測試 24
3.8 浸泡試驗 25
第4章 結果與討論 26
4.1 FeCoNiCrAl0.5高熵合金顯微組織及成份分析 26
4.1.1 鑄態高熵合金的顯微組織及成份分析 26
4.1.2 時效熱處理高熵合金的顯微組織及成份分析 27
4.2 X-ray繞射 30
4.3 硬度 32
4.4 恆電位儀極化 33
4.4.1 1N NaOH水溶液電化學實驗 33
4.4.2 3.5% NaCl水溶液電化學實驗 37
4.4.3 1N H2SO4水溶液電化學實驗 41
4.5 浸泡腐蝕重量損失 57
第5章 結論 64
參 考 資 料 66

1.M. Koberna and J. Fiala, “Intermetallic phases influencing the behaviour of Al-Cu joints “, J. Phys. Chem. Solids, Vol. 54 (1993), pp. 595-601.
2.葉均蔚, 和陳凱瑞, “高熵合金” , 科學發展, 377期 (2004), pp. 16-21.
3.P. K. Huang, J. W. Yeh, T. T. Shun, and S. K. Chen, “Multi-principal element alloys with improved oxidation and wear resistance for thermal spray coating”, Advance Engineering Materials, Vol. 6 (2004), pp. 74-78.
4.J. W. Yeh, S. K. Chen, S. J. Lin, J. Y. Gan, T.S. Chin, T. T. Shun, C. H.Tsau, and S. Y. Chang, “Nanostructured high-entropy alloys with multi-principal elements -- novel alloy design concepts and outcomes”, Advance Engineering Materials, Vol. 5 (2004), pp. 299-303.
5.A. Inoue, “Stabilization of metallic supercooled liquid and bulk amorphous alloys”, Acta Mater., Vol. 48 (2000), pp. 279-306.
6.Y. J. Hsu, W. C. Chiang, and J. K. Wu, “Corrosion behavior of FeCoNiCrCux high entropy alloys in 3.5% NaCl Solution”, Materials Chemistry and Physics, Vol. 92 (2005), pp. 112-117.
7.Y. Zhou, J. Zhang, T. H. North, Z. Wang, “The mechanical properties of friction welded aluminium-based metal-matrix composite materials”, Journal of Materials Science, Vol. 32 (1997), pp. 3883-3889.
8.V. Medeleiene and A. Kosenko, “Structural and functional properties of electrodeposited copper metal matrix composite coating with inclusions of WC”, Materials Science, Vol. 14 (2008), pp. 29-33.
9.C. M. Ward-Close, R. Minor, and P. J. Doorbar, “Intermetallic-matrix composites—a review”, Intermetallics , Vol. 4 (1996), pp. 217-229.
10.葉均蔚, “具奈米結構之多元高熵合金系統” , 知識創新, 40期 (2003), pp. 1-4.
11.Y. Y. Chen, T. Duval, U. D. Huang, J. W. Yeh, and P. K. Huang, “Micro- structure and electrochemical properties of high entropy alloys—a comparison with type-304 stainless steel”, Corrosion Science, Vol. 47 (2005), pp. 2257-2279.
12.U. S. Hsu, U. D. Hung, J. W. Yeh, S. K. Chen, Y. S. Huang, and C. C. Yang, “Alloying behavior of iron, gold and silver in AlCoCrCuNi-based equimolar high-entropy alloys”, Materials Science and Engineering: A, Vol. 460-461 (2007), pp. 403-408.
13.W. A. Oates, “Configurational entropies of mixing in solid alloys”, Journal of Phase Equilibria and diffusion, Vol. 28 (2007), pp. 79-89.
14.C. Y. Hsu and J. W. Yeh, “Wear Resistance and High-Temperature Compres- sion Strength of FCC CuCoNiCrAl0.5Fe Alloy with Boron Addition”, Metallurgical and Materials Transactions A, Vol. 31A (2004), pp. 1465-1469.
15.S. Ranganathan, “Multimatallic cocktails”, Current Sci., Vol. 85 (2003), pp. 1404-1406.
16.Karl E. Spear and Mark D. Allendorf, “Thermodynamic analysis of alumina refractory corrosion by sodium or potassium hydroxide in glass- melting furnaces”, Journal of The Electrochemical Society, Vol. 149 (2002), pp. 551-559.
17.Z. Jialiang and K. Akira, “Corrosion resistance of Al2O3+ZrO2 composite coatings sprayed on stainless steel substrates”, Transaction of JWRI, Vol. 34 (2005), pp. 17-22.
18.陳廷傑, ”簡單相高熵合金AlxCoCrFeNi (0 ≦ x ≦ 2)之電性質研究” , 國立清華大學材料科學與工程研究所碩士論文 (2005), pp. 73-197.
19.M. C. Baykul, “Preparation of shape gold tips for STM by using electro- chemical etching method”, Materials Science and Engineer B, Vol. 74 (2000), pp. 229-233.
20.A. V. Benedetti, P. T. A. Sumodjo, K. Nobe, P. L. Cabot, and W. G. Proud, “Electrochemical studies of copper, copper-aluminum and copper -aluminum-silver”, Electrochemica Acta, Vol. 40 (1995), pp. 2657-2668.
21.Y. Tomita, Y. Hasegawa, and K. Kobayashi, “Nano-scale Cu metal patterning by using an atomic force microscope”, Applied Surface Science, Vol. 244 (2005), pp. 107-110.
22.J. Kunze, V. Maurice, L. H. Klein, H. H. Strehblow, and P. Marcus, “In situ STM study of the effect of chlorides on the initial stages of anodic oxidation of Cu(111) in alkaline solutions.”, Electrochemica Acta, Vol. 48 (2003), pp.1157-1167.
23.C. Garcia, F. Martin, P.de Tiedra, Y. Blanco, and M. Lopez, “Pitting corrosion of welded joints of austenitic stainless steels studied by using an electrochemical minicell ”, Corrosion Science, Vol. 50 (2008), pp. 1184-1194.
24.S. J. Ahn, H. S. Kwon, and D. D. Macdonald, “Role of chloride ion in passivity breakdown on ion and nickel”, Journal of the electron- chemical Society, Vol. 152 (2005), pp. 482-490.
25.J. Datta, C. Bhattacharya, and S. Bandyopadhyay, “Influence of Cl-, Br-, NO3-, and SO42- ions on the corrosion behavior of 6061 Al alloy”, Bull. Mater. Sci., Vol. 28 (2005), pp. 253-258.
26.J. colin, S. Serna, B. Campillo, O. Florez, and J. G. Gonzalez-rodriguez, “Corrosion performance of a rapidly solidified NiAl intermetallic macro- allolled with Fe in 0.5M H2SO4”, Int. J. Electrochem. Sci., Vol. 2 (2007), pp. 947-957.
27.Haynes and Baboian, “Laboratory Corrosion Test and Standards”, ASTM Special Technical Publication; 866, (Texas Instruments, Incorporate, USA (1983) , pp. 69-72.
28.B. O. Oni, N. O. Egiebor, N. J. Ekekwe, and A. Chuku, “Corrosion behavior of Tin-plate carbon steel and aluminum in NaCl solution using electrochemical impedance spectroscopy”, Journal of Minerals & Materials Characterization & Engineering, Vol. 7 (2008), pp. 331-346.
29.J. M. Wu, S. J. Lin, J. W. Yeh, S. K. Chen, Y. S. Huang and H. C. Chen, “Adhesive wear behavior of AlxCoCrCuFeNi high-entropy alloys as a function of aluminum content”, Wear, Vol. 261 (2006), pp. 513-519.
30.G. K. Dey, “Physical metallurgy of nickel aluminides”, Sadhana, Vol.28 (2003), pp.247-262.
31.Y. Y. Chen , U. T. Hong, H. C. Shih, J. W. Yeh, and T. Duval, “Electro- chemical kinetics of the high entropy alloys in aqueous enviroments–a comparison with type-304 stainless steel”, Corrosion Science, Vol. 47 (2005), pp. 2679-2699.
32.T. K. Chen, M. S. Wong, T. T. Shun and J. W. Yeh, “Nanostructured nitride films of multi-element high-entropy alloys by reactive DC sputtering”, Surface & Coatings Technology, Vol. 200 (2005), pp. 1361- 1365.
33.J. R. Regina, J. N. DuPont, and A. R. Marder, “The effect of water vapor on passive-layer stability and corrosion behavior of Fe-Al-Cr base alloys”, Oxidation of Metal, Vol. 61 (2004), pp. 69-90.
34.G. Okamoto, “Passive film of 18-8 stainless steel structure and its function”, Corrosion Sci., Vol. 13 (1973), pp. 471-489.