簡易檢索 / 詳目顯示

回結果列表
研究生： 魏子翔
Wei, Tzu-Hsiang
論文名稱： 高熵複合材料之合金基地相研究
Research on Matrix of High-Entropy Composite Materials
指導教授： 蔡哲瑋
Tsai, Che-Wei
口試委員: 葉均蔚
Yeh, Jien-Wei
陳育良
Chen, Yu-Liang
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： 2019
畢業學年度： 107
語文別： 中文
論文頁數： 132
中文關鍵詞： 耐火高熵合金 、熱分析 、複合材料 、機械性質
外文關鍵詞： Refractory high-entropy alloys, Composites, Mechanical properties, Thermal anaylsis
相關次數： 點閱：3  下載：0 
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報

    • 近年來渦輪引擎效能逐漸提升，引擎工作溫度同時也逐漸升高，已逼近商用超合金的熔點。最根本的解決辦法就是使用更耐高溫之材料，耐火高熵合金 (Refractory High-Entropy Alloys) 最有潛力作為新一代高溫材料而被廣泛的研究，期望能克服高溫時材料的使用限制。但耐火元素偏高的密度成為發展航太引擎的桎梏，若將密度較低的耐高溫陶瓷纖維與具有高溫韌性的耐火高熵合金結合，開發出耐火高熵合金基複合材料，兩者取長補短，更具有發展優勢。
    本研究為開發耐火高熵合金基複合材料之基地相，作為先前研究，目標為開發出適合熔滲法 (Infiltration Process) 之耐火高熵合金。本研究分為四個部分，前三部份結果顯示Si的添加導致合金出現矽化物，而該矽化物在高溫時不易消除，Cr和Si同時添加會讓合金出現更多相偏析，對合金機械性質產生不良的影響，同時合金系統內強鍵結元素亦會使陶瓷強化相發生反應生成無法預期之化合物。
    第四部份則根據前三部分設計出新型CrMoNbTaTiZr系統耐火高熵合金，其理論熔點為2000℃ 以下，低於常見之陶瓷強化相，實驗結果顯示高溫下Cr含量若過多則會產生無法消除之Laves相，對於未來複材製程增加變數，更使合金樹枝內部分液化，最後減少Cr含量能使Laves相能夠全數回溶，在高溫時呈現單相，成功設計出適合熔滲法之耐火高熵合金基地相。

    In recent years, the efficiency of the aerospace engine has gradually increased, and the operating temperature of the engine has also gradually increased, which has approached the melting point of commercial superalloys. The most fundamental solution is to use materials that are more resistant to high temperatures. Refractory High-Entropy Alloys are the most promising as a new generation of high-temperature materials and are expected to overcome the limitations of materials used at high temperatures. However, the high density of refractory elements has become the shackles for the development of aerospace engines. If high-temperature-resistant ceramic fibers with lower density are combined with refractory high-entropy alloys that have high temperature toughness, a refractory high-entropy alloy matrix composite is developed.
    This study is to develop a matrix phase for refractory high-entropy alloy-based composites. As a previous study, the goal was to develop a refractory high-entropy alloy suitable for the infiltration process. The study is divided into four parts. The first three results show that the addition of Si leads to the occurrence of silicides in the alloys, which is difficult to eliminate at high temperatures. The simultaneous addition of Cr and Si causes more phase segregation in the alloy and bad influences on the mechanical properties of the alloy. The strong bonding elements in the alloy system also cause the strengthening phase to react to form unpredictable compounds.
    In the fourth part, the new CrMoNbTaTiZr system refractory high-entropy alloy is designed according to the first three parts. The theoretical melting point is below 2000 °C, which is lower than commercial ceramic strengthening compounds. The experimental results show that if the Cr content is too much, it will form insoluble Laves phase, which makes more uncertainty to the future process. Reducing the Cr content enables to dissolve all Laves phase back in the matrix, and the alloy exhibits single phase at high temperatures. A new high-entropy composites matrix is designed which is suitable for infiltration process.

    摘要 II Abastcat VIII 目錄 X 圖目錄 XIV 表目錄 XX 壹、 前言 1 貳、 文獻回顧 3 2-1 高熵合金 3 2-1.1 高熵合金定義[1, 2] 3 2-1.2 高熵合金的四大核心效應 4 2-2 耐溫材料 11 2-2.1 鎳基超合金發展與應用 11 2-2.2 傳統耐火合金 12 2-2.3 鈮合金[10] 15 2-3 耐火高熵合金 (RHEA) 17 2-3.1 MoNbTaVW合金系統[11, 25] 17 2-3.2 HfNbTaTiZr合金系統[19, 30] 19 2-3.3 HfMoNbTaTiZr合金系統[31, 32] 21 2-3.4 Cr添加對耐火高熵合金性質影響[20] 31 2-3.5 Si添加對耐火高熵合金性質影響[17] 38 2-4 複合材料[36] 41 2-5 熔滲法製程 (Infiltration)[37] 42 參、 研究方法 44 3-1 實驗流程 44 3-2 實驗流程圖 47 3-3 合金製備 48 3-4 微結構與晶體繞射分析 50 3-4.1 X光繞射分析 (XRD) 50 3-4.2 掃描式電子顯微鏡 (SEM) 50 3-5 機械性質分析 51 3-5.1 硬度試驗 51 3-5.2 室溫壓縮試驗 51 3-5.3 高溫壓縮試驗 51 3-6 其他性質分析 53 3-6.1 熱膨脹分析儀 (Dilatometer, DIL) 53 3-6.2 相模擬分析 (Thermo-Calc Software) 53 3-6.3 合金元素基本性質[38] 54 3-6.4 元素之間的混合焓 (kJ．mol-1)[39] 55 肆、 結果與討論 56 4-1 第一系列 56 4-1.1 合金設計 56 4-1.2 微結構與晶體結構分析 59 4-1.3 機械性質 66 4-1.4 熱膨脹分析 68 4-2 第二系列 73 4-2.1 合金設計 73 4-2.2 微結構與晶體結構分析 74 4-2.3 機械性質 78 4-3 第三系列 80 4-3.1 合金設計 80 4-3.2 微結構與晶體結構分析 82 4-3.3 機械性質 88 4-3.4 熱膨脹分析 92 4-4 第四系列 99 4-4.1 合金設計 99 4-4.2 鑄造態微結構分析 102 4-4.3 晶體結構分析 105 4-4.4 壓縮測試 106 4-4.5 高溫相穩定研究 118 伍、 結論 126 陸、 本研究之貢獻與未來研究方向 128 柒、 參考文獻 129

    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. Miracle, D.B. and O.N. Senkov, A critical review of high entropy alloys and related concepts. Acta Materialia, 2017. 122: p. 448-511.
    3. Jien-Wei, Y., Recent progress in high entropy alloys. Ann. Chim. Sci. Mat, 2006. 31(6): p. 633-648.
    4. Yeh, J.W., et al., Formation of simple crystal structures in Cu-Co-Ni-Cr-Al-Fe-Ti-V alloys with multiprincipal metallic elements. Metallurgical and Materials Transactions a-Physical Metallurgy and Materials Science, 2004. 35A(8): p. 2533-2536.
    5. Tong, C.-J., et al., Microstructure characterization of Al x CoCrCuFeNi high-entropy alloy system with multiprincipal elements. Metallurgical and Materials Transactions A, 2005. 36(4): p. 881-893.
    6. Ranganathan, S., Alloyed pleasures: multimetallic cocktails. Current science, 2003. 85(5): p. 1404-1406.
    7. Sims, C.T., 70-GT-24. 1970, USA: ASTM Tech. Pub.
    8. Perepezko, J.H., The Hotter the Engine, the Better. Science, 2009. 326(5956): p. 1068-1069.
    9. Sims, C.T. and W.C. Hagel, The Superalloys. 1972, New York: John Wiley & Sons.
    10. Bewlay, B.P., et al., A review of very-high-temperature Nb-silicide-based composites. Metallurgical and Materials Transactions a-Physical Metallurgy and Materials Science, 2003. 34A(10): p. 2043-2052.
    11. Senkov, O.N., et al., Refractory high-entropy alloys. Intermetallics, 2010. 18(9): p. 1758-1765.
    12. Yurchenko, N.Y., et al., Effect of Cr and Zr on phase stability of refractory Al-Cr-Nb-Ti-V-Zr high-entropy alloys. Journal of Alloys and Compounds, 2018. 757: p. 403-414.
    13. Yurchenko, N., N. Stepanov, and G. Salishchev, Laves-phase formation criterion for high-entropy alloys. Materials Science and Technology, 2017. 33(1): p. 17-22.
    14. Stepanov, N.D., et al., Structure and mechanical properties of the AlCrxNbTiV (x=0, 0.5, 1, 1.5) high entropy alloys. Journal of Alloys and Compounds, 2015. 652: p. 266-280.
    15. Guo, N., et al., Microstructure and mechanical properties of refractory high entropy (Mo0. 5NbHf0. 5ZrTi) BCC/M5Si3 in-situ compound. 2016. 660: p. 197-203.
    16. Liu, C., et al., Microstructure and oxidation behavior of new refractory high entropy alloys. 2014. 583: p. 162-169.
    17. Liu, Y., et al., Microstructure and mechanical properties of refractory HfMo0. 5NbTiV0. 5Six high-entropy composites. 2017. 694: p. 869-876.
    18. 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.
    19. Senkov, O., et al., Microstructure and elevated temperature properties of a refractory TaNbHfZrTi alloy. Journal of Materials Science, 2012. 47(9): p. 4062-4074.
    20. 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.
    21. Lin, C.-M., et al., Effect of Al addition on mechanical properties and microstructure of refractory AlxHfNbTaTiZr alloys. Journal of Alloys and Compounds, 2015. 624: p. 100-107.
    22. 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.
    23. Senkov, O.N., et al., Oxidation behavior of a refractory NbCrMo0.5Ta0.5TiZr alloy. Journal of Materials Science, 2012. 47(18): p. 6522-6534.
    24. Zou, Y., et al., Size-dependent plasticity in an Nb25Mo25Ta25W25 refractory high-entropy alloy. Acta Materialia, 2014. 65: p. 85-97.
    25. Senkov, O.N., et al., Mechanical properties of Nb25Mo25Ta25W25 and V20Nb20Mo20Ta20W20 refractory high entropy alloys. Intermetallics, 2011. 19(5): p. 698-706.
    26. Chen, H., et al., Microstructure and mechanical properties at elevated temperatures of a new Al-containing refractory high-entropy alloy Nb-Mo-Cr-Ti-Al. Journal of Alloys and Compounds, 2016. 661: p. 206-215.
    27. Senkov, O.N., et al., Compositional variation effects on the microstructure and properties of a refractory high-entropy superalloy AlMo0.5NbTa0.5TiZr. Materials & Design, 2018. 139: p. 498-511.
    28. Jensen, J.K., et al., Characterization of the microstructure of the compositionally complex alloy Al1Mo0.5Nb1Ta0.5Ti1Zr1. Scripta Materialia, 2016. 121: p. 1-4.
    29. Senkov, O.N., et al., Development of a Refractory High Entropy Superalloy. Entropy, 2016. 18(3): p. 13.
    30. 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.
    31. Juan, C.-C., et al., Enhanced mechanical properties of HfMoTaTiZr and HfMoNbTaTiZr refractory high-entropy alloys. 2015. 62: p. 76-83.
    32. 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. 國立清華大學材料科學工程研究所, 2016. 博士論文.
    33. 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.
    34. Sengupta, A., et al., Tensile behavior of a new single-crystal nickel-based superalloy (CMSX-4) at room and elevated temperatures. Journal of Materials Engineering and Performance, 1994. 3(5): p. 664-672.
    35. Committee, A.I.H., Properties and selection: Irons, steels, and high performance alloys, in ASM Handbook. 1990, ASM International. p. 960.
    36. Chawla, K.K.J.J., Composite materials: Some recent developments. 1983. 35(3): p. 82-87.
    37. Lemster, K., et al., Activation of alumina foams for fabricating MMCs by pressureless infiltration. Ceramics International, 2007. 33(7): p. 1179-1185.
    38. Guo, S. and C.T. Liu, Phase stability in high entropy alloys: Formation of solid-solution phase or amorphous phase. Progress in Natural Science-Materials International, 2011. 21(6): p. 433-446.
    39. 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.
    40. 周暄苹, AlxCoCrFeNi (0≦x≦2) 高熵合金之導熱、熱膨脹及導電研究. 國立清華大學材料科學工程研究所, 2008. 碩士論文.
    41. 蔡孟哲, 耐火高熵合金 Al-Hf-Mo-Nb-Ta-Ti-Zr 添加 Cr與 Si 對微結構及性質影響之研究. 國立清華大學材料科學工程研究所, 2015. 碩士論文.

    QR CODE