高铌TiAl/Ti600合金电子束焊接头组织与性能
Investigation on the microstructure and mechanical properties of high-Nb TiAl/Ti600 alloy electron beam welded joints
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摘要: 对高铌TiAl/Ti600合金进行了电子束焊接试验以便对高温钛合金与高铌TiAl合金高质焊接提供理论及试验依据，采用金相显微镜、扫描电子显微镜及X射线衍射仪等设备对焊接试样进行了分析.结果表明，高铌TiAl/Ti600接头极易产生裂纹缺陷.接头焊缝主要形成细针状α2-Ti3Al相及α-Ti相，而高铌TiAl侧热影响区呈现板条状及等轴组织形貌，Ti600侧热影响区为针状α'相.接头焊缝区硬度最大，达到586 HV，Ti600侧向高铌TiAl侧过渡过程中硬度逐渐增大，由焊缝到两侧热影响区硬度过渡梯度较大.高铌TiAl/Ti600电子束焊接头室温抗拉强度可达516 MPa，且接头断裂于偏高铌TiAl侧焊缝区，断裂性质为典型的脆性解理断裂，呈现穿晶断裂特征.Abstract: The electron-beam welding of high-Nb TiAl/Ti600 alloy was investigated in this paper to provide theoretical and experimental basis for the high-quality welding of high-Nb TiAl/Ti600. In this paper, optical microscopy, scanning electron microscopy and X-ray diffraction equipment are used to analyze the welding samples. The results showed that the joint was susceptible to solid-state cracking. Owing to fast cooling rate of electron beam welding, the acicular α2-Ti3Al phase and a little α-Ti phase were formed in the FZ (fusion zone), while the HAZ (heat affected zone) of high-Nb TiAl was composed of laths and equiaxial microstructure, and the acicular α'phase precipitated from the HAZ of Ti600 alloy. The joint exhibited a peak value in micro-hardness that occurred at the far end of FZ near the fusion line of high-Nb TiAl alloy and the hardness decreased from the weld seam to the both sides of base metals. The ultimate tensile stress of the as-welded specimen was 516 MPa, and the fracture occurred at the FZ on the side of TiAl alloy. It exhibited brittle cleavage fracture mode and also presented a characteristic of transgranular fracture.
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Keywords:
- Ti600 alloy /
- high-Nb TiAl alloy /
- electron beam welding /
- microstructure /
- mechanical properties
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[1] 姜旭峰, 彭著良, 费逸伟. 航空发动机减重技术研究[J]. 航空维修与工程, 2005 (1): 54-56. Jiang Xufeng, Peng Zhuliang, Fei Yiwei. The study on aero-engine reducing weight techniques[J]. Engineer & Technology, 2005(1): 54-56. [2] Kim B G, Kim G M, Kim C J. Oxidation behavior of TiAl-X(X=Cr, V, Si, Mo or Nb) intermetallics at elevated temperature[J]. Scripta Metallurgica et Materialia, 1995, 33(7): 1117-1125. [3] 陈国良, 林均品. 有序金属间化合物结构材料物理金属学基础[M]. 北京: 冶金工业出版社, 1999. [4] 何 鹏, 冯吉才, 韩杰才, 等. TiAl金属间化合物及其连接技术的研究进展[J]. 焊接学报, 2002, 23(5): 91-96. He Peng, Feng Jicai, Han Jiecai, et al. Advances in TiAl intermetallics and its joining technology(Ⅱ)-advances in TiAl intermetallics[J]. Transactions of the China Welding Institution, 2002, 23(5): 91-96. [5] 陈国庆. TiAl金属间化合物电子束焊接接头组织及防裂纹工艺研究[D]. 哈尔滨:哈尔滨工业大学, 2007. [6] 张秉刚, 陈国庆, 何景山, 等. Ti-43Al-9V-0.3Y/TC4 异种材料电子束焊接 (EBW)[J]. 焊接学报, 2007, 28(4): 41-44. Zhang Binggang, Chen Guoqing, He Jingshan, et al. Electron beam welding of dissimilar metal between Ti-43Al-9V-0.3Y and TC4[J]. Transactions of the China Welding Institution, 2007, 28(4): 41-44. [7] Mallory L,Baeslaek ш W, Philips D. Evolution of the weld heat-affected zone microstructure in a Ti-48Ai-2Cr-2Nb gamma titanium aluminide[J]. Journal of Materials Science Letters, 1994, 13(14): 1061-1065. [8] Chaturvedi M C, Richards N L, Xu Q. Electron beam welding of a Ti-45Al-2Nb-2Mn+0.8 vol.% TiB2 XD alloy[J]. Materials Science and Engineering: A, 1997, 239: 605-612. [9] 黄伯云, 李成功, 石力开, 等. 中国材料工程大典有色金属材料工程[M]. 北京: 化学工业出版社, 2006. [10] 张永刚. 金属间化合物结构材料[M]. 北京: 国防工业出版社, 2001. [11] 吴会强, 冯吉才, 何景山, 等. 电子束焊接TiAl基合金接头组织结构及其裂纹产生的敏感性[J]. 材料工程, 2005(4): 7-10. Wu Huiqiang, Feng Jicai, He Jingshan, et al. Structure and crack forming susceptibility of TiAl based alloy joints by electron beam welding[J]. Journal of Materials Engineering, 2005(4): 7-10. [12] 张喜燕, 赵永庆, 白晨光. 钛合金及应用[M]. 北京: 化学工业出版社, 2005.
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