6063铝合金阶梯钎焊钎料、钎剂及工艺研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
铝及铝合金是有色金属中应用最广泛的结构材料,其中6063铝合金具有良好的成型性能、机械加工性能、焊接性能和抗腐蚀性能而广受关注。目前,国内外雷达发射、接收机箱、信号处理机箱广泛采用6063铝合金材料,随着相控阵等先进体制机载雷达的研制生产,为了实现更高的功率密度和高可靠性,铝合金雷达机箱的结构设计日趋复杂,机箱的焊接需要采用“阶梯钎焊”工艺以实现雷达轻量化、高可靠性的目标。根据以上特点,本文寻找出适用于保护气氛炉中高、中温阶梯钎焊6063铝合金的钎料和改进型钎剂,同时研究了钎焊工艺的优化参数。
     运用正交试验法,通过改变Si,Cu,Ni,RE元素的配比,研究含量的变化对Al-Si-Cu-Ni-RE钎料的熔点、铺展性以及抗剪强度的影响,并通过扫描电镜及能谱分析了钎料内部显微组织;通过研究发现,钎料的成分及加热温度是影响铺展面积的主要因素;对钎料显微组织分析可知,钎料中黑色的脆性θ(Cu Al2)相和区域偏析的絮状相不利于接头的性能,而具有面心立方固溶体的基体相α(Al)以及球状聚集的Si相,使得钎料的力学性能优良。结果表明,Cu元素对钎料熔点的影响最大,其次为Ni,Si,RE元素,钎料的熔点随着Cu含量的增加而急剧下降。选用CsF-AlF_3钎剂和KF-AlF_3钎剂,研究了两种钎剂在6063铝合金表面不同温度下的去
     膜效果,分析和探讨了钎剂与6063铝合金表面氧化膜的反应机制。研究发现,CsF-AlF_3钎剂是以反应、溶解的机制去除6063铝合金表面氧化膜的,NH4F在高温下生成的HF是CsF-AlF_3钎剂去膜的关键化合物。此外,H2O的存在或形成促进了HF的生成,从而加速了钎剂的去膜进程。CsF-AlF_3钎剂反应产物中没有发现CsF和AlF_3,只有少量的CsAlF4存在。在570℃下,KF-AlF_3钎剂反应产物中以KAlF4为主,而在610℃条件下,KAlF4已不存在,只有少量的KMgF3生成。研究还表明,在610℃条件下,Mg、Mn元素和KAlF4将逐渐地消耗掉,使得钎剂熔点急剧升高,导致钎剂流动性变差。
     研究和探讨钎焊参数对6063铝合金的中温钎焊接头硬度强度、显微组织和耐腐蚀等的影响。研究表明:在高温钎剂配合下,升温速率在15℃/min以上时钎料即可获得良好铺展,而配合中温钎剂时,对升温速率的要求高于高温钎剂。分别测试了焊后固溶处理、固溶加时效处理及钎焊状态下三种钎焊接头的显微硬度。结果表明:时效处理后的接头硬度最大,钎缝与母材硬度相差不大;固溶处理接头的钎缝处及扩散区显微硬度明显高于母材;钎焊状态下钎缝硬度也较母材硬度高。测试了不同钎焊温度得到的这三种状态的接头剪切强度。结果表明:钎焊温度为560℃的接头剪切强度最高,钎焊温度越低强度越低。观察并分析了升温速率及保温时间对接头显微组织的影响。结果表明:升温速率较慢时,CuAl2枝晶分散不均匀,保温时间过长则Si晶较粗大,CuAl2枝晶变化不明显。
     采用正交试验法,通过改变Si、Cu、Ni以及混合稀土RE的配比,研究了含量的变化对Al-Si-Cu-Ni-RE钎料的自腐蚀电位、失重质量、腐蚀速率的影响,并通过扫描电镜观察分析了腐蚀前后钎料的内部显微组织。研究发现,钎料的自腐蚀电位与失重质量相对应,随着腐蚀电位的负值增加,失重质量也不断增大。对各元素对腐蚀速率影响的情况分析结果表明,对钎料腐蚀速率的影响依次为Ni的影响最大,其次为Si、Cu、RE。对钎料腐蚀前后的显微组织观察分析可知,Cl-是诱发钎料点蚀的主要原因。腐蚀后的钎料局部区域出现了点蚀,腐蚀后的钎料有明显的网纹状晶间腐蚀。
The aluminum and its alloys are widely used as a kind of structural materials, especially the aluminum alloy 6063 is very popular due to its good properties of formability, mechanism weldability and corrosion resistance. The chassis of radar transmitter, receiver and signal processing are manufactured with 6063 in the world. In order to light the weight and improve the reliability, the stepped brazing process is required to braze the radar chassis because of the complicated structure. In this paper, brazing alloys as well as the matched fluxes, which are suitable for brazing 6063 in high and medium temperature with shielding gas furnace, are studied. In the meantime, parameters of brazing process are optimized.
     The effect of contents on the melting points, spreading property and shear strength of Al-Si-Cu-Ni-RE is researched by changing the level of Si、Cu、Ni、RE according to orthogonal test method. The microstructure of brazing metal is analyzed with SEM and EDS. The results show that the spreading area is dominated by the composition of filler metal and brazing temperature; The black brittle phaseθ(Cu Al2) and macrosegregation flocculent phase decrease the performance of the joint, while the matrix phaseα(Al) with face-centered cubic solid solution and Si phase with conglobulation feature make the performance of the joint better; Cu is the main factor that influences the melting points of the filler metal, next is Ni, Si and RE. The melting points of filler metal sharply lows as the Cu content increases.
     CsF-AlF_3 and KF-AlF_3 series fluxes are selected to research the effect of the fluxes on removing the oxide film of aluminum alloy 6063 at varied temperature. The reaction mechanism of flux with surface oxide film of aluminum alloy 6063 was analyzed and discussed. The results show that reaction and solution are the mechanism of CsF-AlF_3 removing surface oxide film from Al-alloy 6063 and the HF generated from NH4F at high temperature is the key compound. Moreover, the presence or formation of H2O accelerates the generation of HF, which accelerates the Striping rate of oxide film accordingly. No CsF and AlF_3 except a little of CsAlF4 was found in the reaction product of CsF-AlF_3 flux. The main product of KF-AlF_3 flux is KAlF4 at 570℃and a small amount of KMgF3 but no KAlF4 at 610℃. The results also indicates that Mg, Mn and KAlF4 will be gradually consumed at 610℃, which lead to sharp increasing of melting point and worse flowing property of the flux..
     The effect of brazing parameters on the hardness, strength, microstructure, and corrosion resistance of 6063 brazing joint is studied. The results show that with high temperature flux, the brazing metal spreads well above the heating rate of 15℃/min, but with intermediate flux, requires for heating rate will be higher than high temperature flux. Micro hardness of three kinds of brazing joints with different treatment is tested. Results indicate that Micro hardness of brazing joint after aging is the highest, of which hardness of the brazing seam and base metal is almost equal. Hardness of brazing seam and its diffusion area of brazing joint after solution is obviously higher than base metal’s. Hardness of brazing seam after brazing is higher than base metal’s, either. Shear strength of three kinds of brazing joints at different brazing temperature is tested. The results show that shear strength of brazing joint at 560℃is the highest, which decreases with brazing temperature. Effect of heating rate and holding time on microstructure of brazing joint is analyzed. Conclusion indicates that CuAl2 dendrites distribute unevenly at slow heating rate and Si grain becomes coarse but CuAl2 dendrites don’t change significantly after long holding time.
     Effect of contents of Si, Cu, Ni and RE on the corrosion potential, weight loss and corrosion rate of Al-Si-Cu-Ni-RE is studied by changing the level of Si, Cu, Ni and RE according to orthogonal test method. The microstructure is observed with SEM and EDS before and after corrosion test. The results show that the corrosion potential is corresponding to weight loss, the weight loss increased with the decrease of corrosion potential. Ni is the dominant factor that influences corrosion rate, followed by Si, Cu, RE. Cl- is the main reason of inducing brazing metal to pit. Pitting occurred on local area of brazing metal which has obviously reticulate pattern intercrytalline corrosion.
引文
[1] Brown L. A radar history of world warⅡ: technical and military imperatives[M]. Taylor & Francis Group, 1999, 10-12.
    [2]宗伟.先进制造技术在现代雷达电子装备中的发展趋势[J].电子机械工程, 2003, 19(3): 1-3.
    [3] Huang J, Wu Z, Xiang J W. Assessment of aircraft combat survivability enhanced by combined radar stealth and onboard electronic attack [J]. Transactions of Nanjing University of Aeronautic & Astronautics, 2000, 17(2): 150-155.
    [4]许体仁.从机载雷达的发展看精密制造技术[J].航空精密制造技术, 1993, 29(1): 4-5.
    [5]张润逵,戚仁欣等.雷达结构与工艺[M].北京:电子工业出版社, 2007,21-27.
    [6]朱宏,程肇德,赵仁祥.机载电子设备铝合金箱体氮气保护钎焊工艺[J].电子机械工程. 2000, 83(1): 54-57.
    [7]徐胜,徐道荣.铝及铝合金钎焊技术的研究现状[J].轻合金加工技术, 2004, 32(1): 1-4.
    [8] Cooke W E, Wright T E,Hirschfield J A. Furnace brazing of aluminum with a non-corrosive flux[J]. Welding Journal, 1978, 12: 23-28.
    [9] Takemoto T, Shibutani T,Matsunawa A. Chemical reaction of non-corrosive flux with magnesium containing aluminum alloys and the improvement of brazability. [J]. Journal of light mental welding and constraction,1997,35(1):26。
    [10]川濑宽,アルミニウムろう付技术の现状と工业生产への应用[J].轻金属溶接,1990,28(4):153-165.
    [11]川濑宽非腐蚀性フラツクスろう付におけゐAl-Mg合金のろう付性について[J].轻金属溶接,1990,28(12):534-539.
    [12]王祝堂,田荣璋.铝合金及其加工手册[M].长沙:中南工业大学出版社, 1989: 246-250.
    [13]朱祖芳.铝合金阳极氧化与表面处理技术[M].北京:化学工业出版社, 2004, 37-39.
    [14]熊艳才.铸造铝合金现状及未来发展[J].特种铸造及有色合金, 1998, 4: 1-5
    [15]李元元,郭国文,罗宗强等.高强度铸造铝合金材料研究进展[J].特种铸造及有色合金, 2000, 6: 45-47.
    [16]王祝堂.精密铸造厚板工模具铝合金[J].金属世界, 2006, 2: 36-37.
    [17] Dash M, Makhlouf M. Effect of key alloying elements on the feeding characteristics of aluminum-silicon casting alloys[J]. Journal of Light Metals, 2001, 1 (4): 251-265.
    [18]刘志义,李云涛,刘延斌等. Al-Cu-Mg-Ag合金析出相的研究进展[J].中国有色金属学报, 2007, 17(12): 1905-1915.
    [19] Edwards G A, Stiller K, Dunlop G L, et al. The precipitation sequence in Al-Mg-Si alloys[J]. Acta Materialia, 1998, 46(11):3839-3904..
    [20] Huang C, Kou S. Liquation cracking in full-penetration Al-Mg-Si welds[J]. Welding Journal, 2004, 83(4):111-122.
    [21]徐家乐.硅引起6063铝合金型材腐蚀的分析[J].轻合金加工技术, 2001, 29(12): 30-31.
    [22]杨迎新,颜建辉. 6063铝合金化学成分的合理选择[J].加工工艺, 2002, 25(5): 45-46.
    [23]李广钦,左秀荣,宋天福等.变形铝锰系合金的应用现状及发展动态[J].热加工工艺, 2006, 35(10): 63-67.
    [24]王国军,吕新宇. 7055铝合金的化学成分、物相组成及其性能特点[J].上海有色金属, 2008, 29(3): 118-122.
    [25]谢优华,杨守杰,戴圣龙.锆元素在铝合金中的应用[J].航空材料学报, 2002, 22(4): 56-61.
    [26] Chang J, Moon I, Choi C. Refinement of cast microstructure of hypereutectic Al-Si alloys through the addition of rare earth metals[J]. Journal of Materials Science,1998, 33(20):5015-5023.
    [27] Chang J Y, Kim G H. Rare earth concentration in the primary Si crystal in rare earth added Al-21wt.%Si alloy[J]. Scripta Materialia, 1998, 39(3):307-314.
    [28]周晓霞,张仁元,刘银峁.稀土元素在铝合金中的作用和应用[J].新技术新工艺, 2003, 4: 43-44.
    [29]谭锁奎.金属型铸造活塞铝合金中铁的作用研究[J].特种铸造及有色合金, 1998, 3: 31-33.
    [30]王孟君,杨立斌,甘春雷等. 6063铝合金高温流变本构方程[J].华中科技大学学报:自然科学版, 2003, 31(6): 20-22.
    [31]王元良,屈金山.铝合金焊接性能及焊接接头性能[J].中国有色金属学报, 1997, 7(1): 69-74.
    [32]邹僖.钎焊[M].北京:机械工业出版社, 1988: 24-101.
    [33]张勇. X波导的火焰钎焊[J].电子工艺简讯, 1996, 5: 12-13.
    [34]冯杏梅.盐浴铝钎焊去膜机理研究[J].电子机械工程, 2000, 5: 52-54.
    [35]徐道荣,何前进.铝合金空气炉中钎焊的试验研究[J].轻合金加工技术, 2005, 33(9): 44-47.
    [36]胡刚,康慧.铝合金真空钎焊的发展[J].焊接技术, 2001, 2: 1-3.
    [37]朱建国.铝基焊料的应用及发展[J].有色金属与稀土应用, 2000, 2: 128.
    [38]黄路.铝合金钎焊用焊接材料[J].有色金属与稀土应用, 1994, 1: 1-5.
    [39]虞觉奇,陈明安等.快速凝固Al-Si基钎料性能的研究[J].焊接学报, 1994, 15(2): 67-74.
    [40]康慧,胡刚等.铝合金真空钎焊的发展[A].第十次全国焊接会议论文集[C].黑龙江:黑龙江人民出版社, 2001: 231-234.
    [41]张丁非,彭建, Harold D等. Al-Cu-Si合金中的CuAl2相在固溶处理时的溶解对时效后强度的影响[J].材料科学与工艺, 2006, 14(5): 547-551.
    [42]俞伟元,陈学定.快速凝固Al-Si-Cu基钎料的性能[J].焊接学报, 2004, 25(2): 69-72.
    [43]张启运,庄鸿寿.钎焊手册[M].北京:机械工业出版社, 1999: 55-57.
    [44] Tsao L C, Chiang M J, et al. Effects of zinc addition on the microstructure and melting temperatures of Al-Si-Cu filler metals[J]. Materials Characterization, 2002, 48: 341-346.
    [45]邹增大.焊接材料工艺及设备手册[M].北京:化学工业出版社, 2001: 226-267.
    [46] Hellawell. The growth and structure of eutectics with silocon and germanium[J]. Progress on Materials Science, 1970, 15(1): 3-8.
    [47] Schunert T H, Loser W, Teresiak A, et al. Preparation and phase transformations of melt-spun Al–Ge–Si brazing foils[J]. Journal of Material Science, 2004, 32(8): 2181-2189.
    [48]于志刚译,茅本隆司.钎料Al-Ge-Si-Mg的研究[J].轻金属溶接(日), 1995, 33(10): 20-24.
    [49]余燕,吴祖乾.焊接材料选用手册[M].上海:科学技术文献出版社, 2004: 367.
    [50] Wang C H, Kuo C Y. Interfacial reactions between eutectic Sn-Pb solder and Co substrate[J]. Journal of Materials Science, 2011, 46(8):2654-2661.
    [51] Keller J, Baither D, Wilke U, et al. Mechanical properties of Pb-free SnAg solder joints[J]. Acta Materilia, 2011, 59(7):2731-2741.
    [52]龙伟民,乔培新等.自钎剂铝钎料的研制与应用前景[J].焊接设备与材料, 2002, 31(5): 33-34.
    [53] Xia C Z, Li y j, Puchkov U A, et al. Crack analysis near vacuum brazing interface of Cu/Al dissimilar materials using Al-Si brazing alloy[J]. Materials Science and Technology, 2009, 25(3):383-387.
    [54]邹家生,罗新锋,赵宏权. Al-Si-Cu-Zn钎料性能研究[J].焊接技术, 2007, 36(1): 50-52.
    [55]于文花,胡刚. Al-Si-Cu-Ni低熔点钎料中合金元素对其性能的影响[J].焊接2002, 11: 21-23.
    [56]朱颖,胡刚. Al-Si-Cu-Ni低熔点钎料中合金元素含量对接头性能的影响[J].焊接2003, 3:13-16.
    [57]刘志杰等. Ni元素对Al-Si-Cu基真空钎焊接头性能的影响[J].铝加工, 2005, 5: 628.
    [58] Sha M, Wu S S, Zhong G. Variation of microstructure of RE-containing Al-Si-Cu-Ni-RE alloy with different cobalt contents[J]. Journal of Alloys and Compounds, 2011, 509(2):252-257.
    [59] Wang S H, Zhou H P, Kang Y P. The influence of rare earth elements on microstructure and properties of 6061 aluminum alloy vacuum brazed joints[J]. Journal of Alloys and Compounds, 2003, 352: 79-83.
    [60]石保庆.钎焊技术发展动向[J].焊接技术, 1998, 1: 37-38.
    [61]路文江,金彦枫,俞伟元.快速凝固Al-Cu钎料钎焊铝Cu对钎缝组织的影响[J].兰州理工大学学报, 2005, 31(2): 9-12.
    [62]金霞,杨倡进,刘保祥.铝及铝合金用钎剂的发展现状和趋势[J].电子工艺技术, 2008, 29(2): 112-115.
    [63]钱海东,高海燕,王俊.铝用钎剂研究现状及展望[J].材料导报, 2007, 21(12): 76-78.
    [64]吴根华,陈荣,张启运.铝及其合金的无腐蚀、不溶性钎剂钎焊[J].安庆师范学院学报(自然科学版), 1998, 4(3): 51-55.
    [65]尹淑梅,张韵慧.无腐蚀、不溶性钎剂的新进展[J].焊接技术, 2002, 31(3): 45-47.
    [66]张启运,刘淑棋,高念宗.氟铝酸钾高温铝钎剂的湿法合成及其在钎焊时的作用机理[J].焊接学报, 1982, 3(4): 153.
    [67]张启运,刘淑棋,郭海等.熔盐钎剂对铝氧化膜作用过程的研究[J].金属学报, 1985, 21(1): 35.
    [68]张启运,刘淑棋,章于华等.熔盐钎剂与铝氧化膜的相互作用[J].金属学报,1989, 25(2): 121-126.
    [69] Field D J, Steward N I. Mechanistic aspects of the nocolok flux brazing process[J]. Society of Automotive Engineers, 1988: 1656~1664.
    [70] Xue S B, Dong J, Lu X C, et al. Reaction behavior between the oxide film of LY12 aluminum alloy and the flux[J]. China Welding, 2004, 13(1) :36~40.
    [71]张启运,刘淑棋,郭海等.铝及其合金的无腐蚀不溶性钎剂[J].焊接, 1995, 10: 2-6..
    [72]张启运.铝及其合金的无腐蚀不溶性钎剂[J].焊接, 1995, 9: 2-10.
    [73] Chen R, Cao J, Zhang Q. Phase relation in the system AlF3-KF[J]. Thermochimia Acts, 1997, 303: 145.
    [74] Chen R, Zhang Q Y. Investigation of the ternary system AlF3-KF-CsF[J]. Journal of Solid State Chemistry, 2001, 161: 80~84.
    [75]鲍俊娟,高志广,李川等. 2A50铝合金钎焊钎料与钎剂的选择[J].机械工程材料, 2006,30(12): 40~43.
    [76] Xue S B, Qian Y Y, Dong J, et al. Novel approach of LY12 alloy brazing[J]. China Welding, 2003, 12(1):54~56.
    [77]薛松柏,董健,吕晓春等. LY12铝合金中温焊技术[J].焊接学报, 2003, 24(3): 21-22.
    [78]聂存中,张厚安. 6063铝合金型材的力学性能[J].轻合金加工技术, 1993, 21(3): 29-34.
    [79]戴安邦,尹敬执,严志弦,等.无机化学教程(下)[M].北京:高等教育出版社,1958.
    [80]中国机械工程学会焊接学会.焊接手册(第1卷)[M].北京:机械工业出版社, 2001. 477-481.
    [81] Humpston G, Sangha S P S, Jacobson D M. New filler metals and process for fluxless brazing of aluminum engineering alloys[J]. Materials Science and Technology, 1995, 11 (10): 1161-1167.
    [82]邹家生,吕思聪,赵宏权等. Al-Si-Cu-Zn急冷钎料钎焊铝及铝合金的界面结构及强度[J].焊接学报, 2008, 29(3): 77-80.
    [83] Suzuli K, Kagayama M, Takeuchi Y. Eutectic phase equilibrium of Al-Si-Zn system and its applicability for lower temperature brazing[J]. Journal Japan Institute of Light Metals, 1993, 43(10): 533-538.
    [84]陆洋,王泽华,林萍华,包晔峰,袁鸿斌,冯杏梅,冯展鹰.合金元素对铝-硅基钎料熔点的影响[J].机械工程材料, 2008, 32(9):17~23.
    [85] WangZehua,LuYang,LinPinghua and Jiang Shaoqun. Effects of Cu,Si,Ni and rare earth elements on melting temperature and properties of A1-Si fil1er metals[J]. China Welding, 2009, 18(4):43~46.
    [86]于文花,朱颖,康慧等.合金元素Cu、Si、Ni对铝基钎料的影响[J].焊接技术, 2003, 32(2): 33-35.
    [87]朱宏,冯杏梅,冯展鹰,张国伟,包晔峰.Al-Si-Cu-Ni-RE钎料性能研究[J].焊接,2009,S(1):7~9.
    [88]陆洋,王泽华.低熔点铝硅基钎料的研究[D].南京:河海大学.2008:20~63.
    [89]张国伟.6063铝合金的中温炉中钎焊研究[D].南京:河海大学,2009:50~69.
    [90]朱宏,冯杏梅,冯展鹰,张国伟,包晔峰.6063铝合金冷板中温无腐蚀钎焊工艺研究,焊接,2009,S(1):12~14.
    [91]曹楚南.腐蚀电化学原理[M].北京:化学工业出版社, 2008: 76-77.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700