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研究生: 曾可凱
Tseng, Ko-Kai
論文名稱: 新型耐火高熵合金在核能結構材料之研究及開發
Development of Refractory High Entropy Alloys for Nuclear Structure Materials
指導教授: 葉均蔚
Yeh Jien-Wei
口試委員: 洪健龍
楊智超
孫道中
李英杰
學位類別: 碩士
Master
系所名稱: 工學院 - 材料科學工程學系
Materials Science and Engineering
論文出版年: 2016
畢業學年度: 104
語文別: 中文
論文頁數: 106
中文關鍵詞: 高熵合金核能結構材料耐火高熵合金
外文關鍵詞: refractory high-entropy alloy, nuclear structure materials
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  • 第四代核反應器國際論壇(The Generation IV International Forum, GIF)所提出之第四代核反應器(Generation IV reactor),預計在2030年商轉,其最重要的目的即為取代現行商用的第二代核反應器、提升發電效率、減少污染、防止核武擴散並且提升永續性。但在第四代核反應器中如此嚴苛的工作環境下,尚未有一組材料被真正認可。第四代核反應器最不同的地方,即為其工作流體、工作環境以及輻射劑量。為了提升發電效能以及核反應效率,使用高工作溫度、高輻射劑量或腐蝕性流體,將造成材料機械性、化學性及輻射性更大的損壞。
    本論文研發新型高熵合金,使具有低中子吸收截面、高抗氧化、高溫高強度以及韌性,以作為第四代核能反應器之候選材料。
    本研究設計巨觀中子吸收截面比304不銹鋼低 30% 的 MV 系列高熵合金,並研究其微結構及機械性質。研究顯示,此系列呈現 BCC 簡單固溶體結構,其中MV030-C及 MV050-C 鑄造態在BEI 影像下無樹枝狀結構,MV075-C 以及 MV100-C則有樹枝狀結構。MV030 以及 MV050 在 1200 ˚C/12 h 熱處理後不會出現析出物,相穩定性佳,但 MV075 以及 MV100 在樹枝間相區域會析出 Laves phase,且所析出之 Laves phase 成分相近,可知此系列合金 Laves phase固溶成分界線為:"1.3 < " "(Mo at% + V at%)" /"Zr at%" "< 4" 。1400 ˚C/12h 水淬熱處理可使 MV100 均質化。MV030-C 以及 MV050-C降伏強度為1089及1268 MPa,塑性變形量可達 50% 而不破裂。但隨著 x 增加,室溫降伏強度上升,塑性變形量下降。MV030-C 以及 MV050-C 直到 800 ˚C 以上高溫強度才明顯下降,800 強度為850 MPa,優於單相HfNbTaTiZr的550 MPa,高溫抗軟化性佳。而有樹枝狀結構的 MV075-C 以及 MV100-C 在 600 ˚C 以上軟化較快,但800 ˚C 強度仍分別有780及650 MPa。
    綜合而言,MV050-C 為此系列中最佳的成分,低中子吸收、單相無析出,室溫壓縮量超過 50%,且800 ˚C 強度仍高達850 MPa,因此深具第四代核反應器結構材料的應用潛力。


    In this study, a new design of refractory high-entropy alloy, MV series, for nuclear structure materials is developed. The melting point is around 2000 ˚C. The density is around 7 g/cm3. Macro neutron absorption cross section is around 0.17 cm-1, which is less than SS304 by 30%. Simple BCC structure is observed in the as-cast state of this alloy. The formation of simple solid solution phase mainly results from the high entropy effect and low bonding energies among constituent elements. After 1200 ˚C/12 h heat treatment, MV075 and MV100 will form Laves phase precipitation, but MV030 and MV050 won’t. These alloys have Vickers hardness around 350 to 450 Hv and compression yield strength around 1000 to 1400 MPa. Impressively, MV030-C and MV050-C possess the compression ductility more than 50%. By the high temperature compression test, MV050-C shows good thermal-softening resistance until 800 ˚C, retaining 850 MPa. Comparing to HfNbTaTiZr alloy, MV050-C and HfNbTaTiZr both possess the compression ductility more than 50%, but MV050-C have better compression yield strength until 800 ˚C and better specific yield strength.

    摘要 I Abstract III 致謝 IV 目錄 IX 圖目錄 XIV 表目錄 XXI 壹、 前言 1 貳、 文獻回顧 3 2.1 高熵合金(High-entropy alloys) 3 2.1.1 高熵合金之定義 4 2.1.2 高熵效應(High-entropy effect) 5 2.1.3 嚴重晶格扭曲效應(Severe-lattice-distortion effect) 7 2.1.4 遲緩擴散效應(Sluggish diffusion effect) 11 2.1.5 雞尾酒效應(Cocktail effect) 14 2.2 耐火高熵合金 16 2.2.1 MoNbTaW 與 MoNbTaVW[15, 16] 16 2.2.2 HfNbTaTiZr[17, 18] 19 2.2.3 鉻添加耐火高熵合金 20 2.2.3.1 CrMo0.5NbTa0.5TiZr[19] 20 2.2.3.2 CrNbTiVZr[20, 23] 22 2.2.4 鋁添加耐火高熵合金 22 2.3 核能反應器 25 2.3.1 核反應 26 2.3.2 中子截面(Neutron cross section) 28 2.3.3 爐心組成要素[29] 32 2.3.3.1 燃料 32 2.3.3.2 護套 33 2.3.3.3 控制棒 33 2.3.3.4 緩速劑 34 2.3.3.5 冷卻劑 35 2.3.4 輕水式反應器(Light water reactor) 35 2.3.4.1 沸水式反應器(Boiling water reactor ) 36 2.3.4.2 壓水式反應器(Pressurized water reactor) 37 2.3.5 快中子滋生反應器(Fast breeder reactor) 38 2.3.6 第四代核反應器[30] 40 2.3.6.1 超高溫氣冷式反應器 41 2.3.6.2 超臨界水反應器 42 2.3.6.3 熔鹽式反應器 42 2.3.6.4 快中子滋生反應器型的第四代核反應器 42 2.3.6.5 第四代核反應器的困難與挑戰 45 參、 成分設計與實驗方法 48 3.1 成分設計 48 3.2 試片代號 54 3.3 實驗方法 55 3.3.1 真空電弧熔煉 56 3.3.2 密度量測 56 3.3.3 蝕刻 57 3.3.4 機械性質量測 57 3.3.4.1 硬度量測 57 3.3.4.2 常溫壓縮試驗 57 3.3.4.3 高溫壓縮試驗 58 3.3.4.4 熱輥軋 59 3.3.5 氧化增重試驗 60 3.3.6 微結構觀察 61 3.3.6.1 電子顯微鏡 61 3.3.6.2 X-ray 繞射分析 61 肆、 實驗結果與討論 62 4.1 微結構 62 4.1.1 MV030 62 4.1.2 MV050 67 4.1.3 MV075 71 4.1.4 MV010 75 4.1.5 討論 84 4.2 機械性質 86 4.2.1 硬度 86 4.2.2 室溫壓縮 87 4.2.3 高溫壓縮 88 4.2.4 熱輥軋 91 4.2.5 討論 92 4.3 氧化測試 95 伍、 結論 98 陸、 未來研究工作 100 柒、 參考資料 101

    1. Yeh, J.W., et al., Nanostructured high-entropy alloys with multiple principal elements: Novel alloy design concepts and outcomes. Advanced Engineering Materials, 2004. 6(5): p. 299-303.
    2. YEH, J.-W., Recent Progress in High-entropy Alloys. Annales De Chimie – Science des Materiaux,, 2006. 31(6).
    3. 黃國雄, 等莫耳比多元合金系統之研究, in 國立清華大學材料所. 1996, 國立清華大學.
    4. Zhang, Y., et al., Solid-Solution Phase Formation Rules for Multi-component Alloys. Advanced Engineering Materials, 2008. 10(6): p. 534-538.
    5. Zhang, Y., et al., Microstructures and properties of high-entropy alloys. Progress in Materials Science, 2014. 61: p. 1-93.
    6. Yeh, J.-W., et al., Anomalous decrease in X-ray diffraction intensities of Cu–Ni–Al–Co–Cr–Fe–Si alloy systems with multi-principal elements. Materials Chemistry and Physics, 2007. 103(1): p. 41-46.
    7. 葉均蔚, 高熵合金的發展. 華岡工程學報, 2011. 27 p. 1-18
    8. 李軝, Ni至CoCrFeMnNi等莫耳合金變形行為之比較探討 in 材料科學工程研究所. 2013, 國立清華大學.
    9. Tsai, K.Y., M.H. Tsai, and J.W. Yeh, Sluggish diffusion in Co–Cr–Fe–Mn–Ni high-entropy alloys. Acta Materialia, 2013. 61(13): p. 4887-4897.
    10. 阮建彰, Hf-Mo-Nb-Ta-Ti-Zr耐火高熵合金之微結構及機械性質探討. 2016, 國立清華大學.
    11. 蔡秉修, AlxCoCrFeMnNi(x=0~1)微結構與機械性質之研究, in 材料科學工程學系. 2015, 國立清華大學.
    12. 張天豪, 含硼新型硬面焊合金之磨耗研究, in 材料科學工程學系. 2014, 國立清華大學.
    13. Yeh, A.C., et al., Developing New Type of High Temperature Alloys–High Entropy Superalloys. International Journal of Metallurgical & Materials Engineering 2015. 1( 107).
    14. Michael Bauccio, ASM metals reference book. 1993: ASM International.
    15. Senkov, O.N., et al., Refractory high-entropy alloys. Intermetallics, 2010. 18(9): p. 1758-1765.
    16. Senkov, O.N., et al., Mechanical properties of Nb25Mo25Ta25W25 and V20Nb20Mo20Ta20W20 refractory high entropy alloys. Intermetallics, 2011. 19(5): p. 698-706.
    17. Senkov, O.N., et al., Microstructure and elevated temperature properties of a refractory TaNbHfZrTi alloy. Journal of Materials Science, 2012. 47(9): p. 4062-4074.
    18. Senkov, O.N., et al., Microstructure and room temperature properties of a high-entropy TaNbHfZrTi alloy. Journal of Alloys and Compounds, 2011. 509(20): p. 6043-6048.
    19. Senkov, O.N. and C.F. Woodward, Microstructure and properties of a refractory NbCrMo0.5Ta0.5TiZr alloy. Materials Science and Engineering: A, 2011. 529: p. 311-320.
    20. Senkov, O.N., et al., Mechanical properties of low-density, refractory multi-principal element alloys of the Cr–Nb–Ti–V–Zr system. Materials Science and Engineering: A, 2013. 565: p. 51-62.
    21. Senkov, O.N., S.V. Senkova, and C. Woodward, Effect of aluminum on the microstructure and properties of two refractory high-entropy alloys. Acta Materialia, 2014. 68: p. 214-228.
    22. Senkov, O.N., et al., Oxidation behavior of a refractory NbCrMo0.5Ta0.5TiZr alloy. Journal of Materials Science, 2012. 47(18): p. 6522-6534.
    23. Senkov, O.N., et al., Low-density, refractory multi-principal element alloys of the Cr–Nb–Ti–V–Zr system: Microstructure and phase analysis. Acta Materialia, 2013. 61(5): p. 1545-1557.
    24. Abram, T. and S. Ion, Generation-IV nuclear power: A review of the state of the science. Energy Policy, 2008. 36(12): p. 4323-4330.
    25. 李敏, 核分裂反應器的發展歷程, in 科學月刊. 2011.
    26. Lamarsh, J.R. and A.J. Baratta, Introduction to Nuclear Engineering 2001: Prentice-Hall, Inc.
    27. M. F. Ashby, M.S. Materials for Nuclear Power Systems. 2011.
    28. Ragheb, M. Neutron Cross Sections. 2014.
    29. Gwynne, J.H., Nuclear Materials. 2014, Department of Materials Science and Metallurgy: University of Cambridge.
    30. The Generation IV International Forum. Available from: https://www.gen-4.org/gif/jcms/c_71564/gif-framework-agreement-extended-for-ten-years.
    31. 李敏, Advanced Reactor Concepts and Design Nuclear Power System.
    32. Yvon, P. and F. Carré, Structural materials challenges for advanced reactor systems. Journal of Nuclear Materials, 2009. 385(2): p. 217-222.
    33. Takeuchi, A. and A. Inoue, Classification of Bulk Metallic Glasses by Atomic Size Difference, Heat of Mixing and Period of Constituent Elements and Its Application to Characterization of the Main Alloying Element. MATERIALS TRANSACTIONS, 2005. 46(12): p. 2817-2829.
    34. Sheng GUO, C.T.L., Phase stability in high entropy alloys: Formation of solid-solution phase or amorphous phase. Progress in Natural Science: Materials International 2011. 21.
    35. Baker, H., ASM Handbook Alloy Phase Diagrams 1992: ASM International.
    36. Yang, X. and Y. Zhang, Prediction of high-entropy stabilized solid-solution in multi-component alloys. Materials Chemistry and Physics, 2012. 132(2-3): p. 233-238.
    37. Guo, S., et al., Effect of valence electron concentration on stability of fcc or bcc phase in high entropy alloys. Journal of Applied Physics, 2011. 109(10): p. 103505.
    38. Dong, Y., et al., Effects of electro-negativity on the stability of topologically close-packed phase in high entropy alloys. Intermetallics, 2014. 52: p. 105-109.

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