臺灣博碩士論文加值系統

AA7075高強度鋁合金是一種析出硬化型合金廣泛應用於航空航太、汽車及國防工業，隨著鋁合金廣泛地應用在結構件中，它們必須具備良好的銲接性，這對於高強度鋁合金而言，銲接性不佳是一個長期存在的問題，由於高溫銲接金屬凝固組織不良，且在熔合區產生氣孔缺陷，使機械性質變差；最近，出現一種新的具有發展潛力的銲接方法，係將摩擦攪拌銲接與電弧銲接結合的複合銲接製程，可提高和改善銲接接合品質。在本研究中使用惰氣鎢極電弧銲作為複合裝置，在摩擦攪拌銲接前方提供一個外部預熱源，詳細研究了顯微組織、機械性質及腐蝕特性；此外，也針對兩種銲接製程後的AA7075鋁合金板之銲道特性做比較；研究結果顯示摩擦攪拌複合銲接具有較寬的晶粒細化區，同時硬度也從銲道橫截面的邊緣向中心增加，而且銲件也呈現出較高之抗拉強度與硬度；由X光繞射之分析結果顯示，在摩擦攪拌銲接後，生成一個新的繞射峰(222)，在攪拌區中鋁(面心立方結構)的(111)面繞射強度相對增加，表示摩擦攪拌銲接鋁合金具有優選方向：摩擦攪拌複合銲接可提高了攪拌區中的腐蝕電位並降低了腐蝕電流。

High strength aluminium alloy AA7075 is a precipitate hardenable alloy widely used in the aerospace, automotive and defense sectors. With the continued widespread use in aluminum alloy structural assembly, they must be weldable, which has been a long-standing issue for high strength aluminum alloys, due to poor solidification microstructure, featuring high porosity in fusion zone and lose their mechanical properties when they are welded by conventional fusion welding processes. Recently, a new hybrid welding technology, combining friction stir welding with arc welding which has great potential to produce effective and defect-free joint. In this study, gas tungsten arc welding was used to provide an external pre-heat source in front of the friction stir welding, as a hybrid system. The microstructure, mechanical properties, and corrosion characteristic were investigated in detail. Joints characteristics of aluminium alloy AA7075 plates for two process were also compared. Results showed that hybrid friction stir welds exhibited the wider fine-grained areas. Similarly, the hardness also increased from the edge of the cross-sectioned sample towards the center, and this weldment also exhibited high tensile strength and hardness. A new peak was identified as (222) after friction stir welding from the X-ray diffraction studies. The diffraction intensity ratio of (111) plane corresponding to aluminum (face-centered cubic crystal structure) was relatively increased in the stir zone, which suggested the friction stir welded aluminum alloy has a preferential orientation. Hybrid friction stir welding increased the corrosion potential and decreased the corrosion current in the stir zone.

摘要...i
Abstract...ii
誌謝...iii
目錄...iv
表目錄...vi
圖目錄...vii
第一章 緒論...1
1.1 前言...1
1.2 研究動機與目的...1
第二章 文獻回顧...2
2.1 鋁合金簡介...2
2.1.1 鋁來源與提煉...2
2.1.2 鋁合金的種類...2
2.1.3 7XXX系列鋁合金析出與熱處理硬化機制...5
2.2 摩擦攪拌銲接...7
2.2.1 摩擦攪拌銲接原理...7
2.2.2 摩擦攪拌銲接之優缺點...9
2.2.3 摩擦攪拌銲接之參數...10
2.2.4 摩擦攪拌銲接銲道微觀組織...10
2.2.5 摩擦攪拌銲接之機械性質...12
2.3 摩擦攪拌複合銲接...13
2.3.1 雷射複合摩擦攪拌銲接...13
2.3.2 電弧複合摩擦攪拌銲接...13
2.3.3 電流複合摩擦攪拌銲接...14
2.3.4 超音波震動複合摩擦攪拌銲接...14
2.4 國內外相關研究...17
第三章 實驗方法...20
3.1 實驗流程...20
3.2 摩擦攪拌銲接...20
3.3 顯微組織分析...20
3.4 SEM/EDS元素分析...20
3.5 XRD 相結構分析...20
3.6 硬度測試...21
3.7 電化學腐蝕試驗...21
3.8 拉伸試驗...21
第四章 結果與討論...29
4.1 顯微組織分析...29
4.2 SEM/EDS元素分析...37
4.3 XRD相結構分析...46
4.4 維式硬度測試...47
4.5 電化學極化曲線測試...50
4.5.1 極化曲線分析...50
4.5.2 腐蝕表面形貌觀察...52
4.6 拉伸試驗...61
第五章 結論...65
參考文獻...66
Extended Abstract...70

[1] L. Aucott, D. Huang, H.B. Dong, S.W. Wen, J.A. Marsden, A. Rack, A.C.F.
Cocks, "Initiation and growth kinetics of solidification cracking during
welding of steel," Scientific Reports, 7, 2017, pp.1-10.
[2] Maximilian Sokoluk, Chezheng Cao, Shuaihang Pan, Xiaochun Li,
"Nanoparticle-enabled phase control for arc welding of unweldable aluminum
alloy 7075," Nature Communications, 10(1), 2019, pp.1-8.
[3] R.S. Mishra, Z.Y. Ma, "Friction stir welding and processing," Materials
Science and Engineering: R: Reports, 50(1-2), 2005, pp.1-78.
[4] Shuxing Huan, Yaowu Wang, Jianping Peng, Yuezhong Di, Bo Li, Lida Zhang,
"Recovery of aluminum from waste aluminum alloy by low-temperature molten
salt electrolysis," Minerals Engineering, 154, 2020, pp.1-7.
[5] L. Zheng, A. Soria, "Prospective study of the world aluminum industry," JRC
Scientific and Technical Reports, 2007, pp.46-58.
[6] Daniel Brough, Hussam Jouhara, "The aluminium industry: A review on state-
of-the-art technologies, environmental impacts and possibilities for waste
heat recovery," International Journal of Thermofluids, 1-2, 2020, 100007.
[7] P.L. Threadgill, A.J. Leonard, H.R. Shercliff, P.J. Withers, "Friction stir
welding of aluminium alloys," International Materials Reviews, 54(2), 2009,
pp.49-93.
[8] M. Dixit, R.S. Mishra, K.K. Sankaran, "Structure–property correlations in
Al 7050 and Al 7055 high-strength aluminum alloys," Materials Science and
Engineering: A, 478(1-2), 2008, pp.163-172.
[9] M.O. Speidel, M.V. Hyatt, "Advances in corrosion science and technology,"
Plenum Press, 1(2), 1972, pp.115-127.
[10] Abhishek Ghosh, Manojit Ghosh, Gyan Shankar, "On the role of precipitates
in controlling microstructure and mechanical properties of Ag and Sn added
7075 alloys during artificial ageing," Materials Science and Engineering:
A, 738(19), 2018, pp.399-411.
[11] Yu.N. Gornostyrev, M.I. Katsnelson, “Misfit stabilized embedded
nanoparticles in metallic alloys,” Physical Chemistry Chemical Physics,
17(41), 2015, pp.27249-27257.
[12] Zhi-hong FU, Di-qiu HE, Hong WANG, "Friction stir welding of aluminum
alloys," Journal of Wuhan University of Technology-Mater. Sci. Ed., 19(1),
2004, pp.61-64.
[13] M. Guerraa, C. Schmidta, J.C. McClurea, L.E. Murra, A.C. Nunesb, "Flow
patterns during friction stir welding," Materials Characterization, 49(2),
2002, pp.95-101.
[14] Won-Bae Lee, Yun-Mo Yeon, Seung-Boo Jung, "The joint properties of
dissimilar formed Al alloys by friction stir welding according to the
fixed location of materials," Scripta Materialia, 49(5), 2003, pp.423-428.
[15] L.E. Murr, J.C. Mcclure, "Solid-state flow visualization in the friction
stir welding of 2024 Al to 6061 Al," Scripta Materialia, 40(9), 1999,
pp.1041-1046.
[16] C.G. Rhodes, M.W. Mahoney, W.H. Bingle, R.A. Spurling, C.C. Bampton,
"Effects of friction stir welding on microstructure of 7075 aluminum
alloy," Scripta Materiaila, 36(1), 1997, pp.69-75.
[17] Y. Li, L.E. Murr, J.C. McClure, "Flow visualization and residual
microstructures associated with the friction-stir welding of 2024 aluminum
to 6061 aluminum," Materials Science and Engineering: A, 271(1-2), 1999,
pp.213-223.
[18] J. da Silva, J.M. Costa, A. Loureiro, J.M. Ferreira, "Fatigue behaviour of
AA6082-T6 MIG welded butt joints improved by friction stir processing,"
Materials & Design, 51, 2013, pp.315-322.
[19] 康宗瑋， 鋁合金之摩擦攪拌銲接之實驗， 國立中山大學: 機械與機電工程研究所碩士論文，
2006.
[20] G.K. Padhy, C.S. Wu, S. Gao, "Friction stir based welding and processing
technologies - processes, parameters, microstructures and applications: A
review," Journal of Materials Science & Technology, 34(1), 2018, pp.1-38.
[21] G. Kohn, Y. Greenberg, I. Makover, A. Munitz, "Laser-assisted friction
stir welding," Welding Journal, 81(2), 2001, pp.46-48.
[22] M.W. Mahoney, C.G. Rhodes, J.G. Flintoff, W.H. Bingel, R.A. Spurling,
"Properties of friction-stir-welded 7075 T651 aluminum," Metallurgical and
Materials Transactions A, 29(7), 1998, pp.1955-1964.
[23] G.J. Fernandez, L.E. Murr, "Characterization of tool wear and weld
optimization in the friction-stir welding of cast aluminum 359+20% SiC
metal-matrix composite," Materials Characterization, 52(1), 2004, pp.65-
75.
[24] K.V. Jata, S.L. Semiatin, "Continuous dynamic recrystallization during
friction stir welding of high strength aluminium alloys," Scripta
Materialia, 43(8), 2000, pp.743-749.
[25] F.J. Humphreys, M. Hatherly, "Recrystallization of Ordered Materials," in
Recrystallization and Related Annealing Phenomena, 1996, pp. 269-283.
[26] J.Q. Su, T.W. Nelson, R. Mishra, M. Mahoney, "Microstructural
investigation of friction stir welded 7050-T651 aluminium," Acta
Materialia, 51(3), 2003, pp.713-729.
[27] 張志溢、黃志青， “摩擦旋轉攪拌製程之新近發展與應用，” 科儀新知， 25(4)， 93，
pp.59-73.
[28] W.B. Lee, Y.M. Yeon, S.B. Jung, "The improvement of mechanical properties
of friction-stir welded A356 Al alloy," Materials Science and Engineering:
A, 335(1-2), 2003, pp.154-159.
[29] Y.S. Sato, M. Urata, H. Kokawa, K. Ikeda, "Hall-Petch relationship in
friction stir welds of equal channel angular-pressed aluminum alloys,"
Materials Science and Engineering: A, 354(1-2), 2003, pp.298-305.
[30] T. Khaled, "An outsider looks at friction stir welding," Journal of
Materials Science, ANM-112N-05-06, 2005.
[31] B. Lange, "Effects of Ultrasound on Deformation Characteristics of
Metals," IEEET ransactionson Sonics and Ultrasonics, 13(1), 1966, pp.1-8.
[32] B. Langenecker, "Work Softening of Metal Crystals by Al Ternating the Rate
of Glide Strain," Acta Metallurgica, 9(10), 1961, pp.937-940.
[33] Zhaoyang Yan, Shujun Chen, Xiaoxu Li, Tao Yuan, "Preliminary study of
friction stir overlap welding on variable polarity plasma arc weld,"
Journal of Materials Research and Technology, 9(1), 2020, pp.322-330.
[34] Luo Jian, Li Fei, Chen Wei, “Experimental Researches on Resistance Heat
Aided Friction Stir Welding of Mg Alloy,” Quarterly Journal of The Japan
Welding Society, 31(4), 2013, pp.65-68.
[35] P. Kwanghyun, Development and Analysis of Ultrasonic Assisted, University
of Michigan: Mechanical Engineering, 2009.
[36] Xinjiang Fei, Zhifeng Wu, "Research of temperature and microstructure in
friction stir welding of Q235 steel with laser-assisted heating," Results
in Physics, 11, 2018, pp.1048-1051.
[37] D.K. Yaduwanshi, S. Bag, S. Pal, "Numerical modeling and experimental
investigation on plasma-assisted hybrid friction stir welding of
dissimilar materials," Materials & Design, 92, 2016, pp.166-183.
[38] Fadi Al-Badour, Nesar Merah, Abdelrahman Shuaib, Abdelaziz Bazoune ,
"Thermo-mechanical finite element model of friction stir welding of
dissimilar alloys," Int J Adv Manuf Technol, 72, 2014, pp.607-617.
[39] Yanying Hua, Huijie Liua, Hidetoshi Fujii, "Improving the mechanical
properties of 2219-T6 aluminum alloy joints by ultrasonic vibrations
during friction stir welding," Journal of Materials Processing Technology,
271, 2019, pp.75-84.
[40] F. Ahmadi, M. Farzin, M. Mandegari, "Effect of grain size on ultrasonic
softening of pure aluminum," Ultrasonics, 63, 2015, pp.111-117.
[41] Y.F. Sun, J.M. Shen, Y. Morisada, H. Fujii, "Spot friction stir welding of
low carbon steel plates preheated by high frequency induction," Materials
& Design (1980-2015), 54, 2014, pp.450-457.
[42] G. Madhusudhan Reddy, Amol A. Gokhale, "Welding aspects of aluminum–
lithium alloys," in Aluminum-Lithium Alloys Processing, Properties, and
Applications, 2014, pp. 259-302.
[43] S. Chen, X. Jiang, "Texture evolution and deformation mechanism in
friction stir welding of 2219Al," Materials Science and Engineering: A,
612, 2014, pp.267-277.
[44] Xiaoxu Li, Shujun Chen, Tao Yuan, Xiaoqing Jiang, Yang Han, "Improving the
properties of friction stir welded 2219-T87 aluminum alloy with GTA offset
preheating," Journal of Manufacturing Processes, 51, 2020, pp.10-18.
[45] Yong Chen, Yanqiu Wang, Li zhou, Guozhe Meng, Bin Liu, Junyi Wang, Yawei
Shao, Jiantang Jiang, "Macro-galvanic effect and its influence on
corrosion behaviors of friction stir welding joint of 7050-T76 Al alloy,"
Corrosion Science, 164, 2020, 108360.
[46] 林宜勳， A7075/A7050 高強度鋁合金異質銲接與銲後熱處理之微觀組織與機械性質之研究，
國立交通大學: 工學院精密與自動化工程學程碩士論文， 2012.
[47] 邢立伟，路浩， “铝合金熔化极銲接接头组织分区，” 宇航材料工艺， 47(2)， 2017，
pp.67-70.