Superplastic Deformation Behavior of 7B04 Al Alloy
ZHANG Ning1,2,3, WANG Yao-qi1,2,3, HOU Hong-liang1,2,3, ZHANG Yan-ling1,2,3, DONG Xiao-meng4, LI Zhi-qiang1
1. Beijing Aeronautical Manufacturing Technology Research Institute, Beijing 100024, China;
2. Aeronautical Key Laboratory for Plastic Forming Technology, Beijing 100024, China;
3. Beijing Key Laboratory of Digital Plasticity Forming Technology and Equipment, Beijing 100024, China;
4. University of Science and Technology Beijing, Beijing 100083, China
Abstract：The superplastic tensile tests were carried out for 7B04 Al alloy under a temperature range of 470-530℃ at a strain rate range of 0.0003-0.01s-1. Then,the superplastic deformation behavior and deformation mechanism of the material were investigated. The results show that with the increase of temperature and decrease of strain rate, the flow stress of 7B04 Al alloy is decreased and the elongation is increased.When the deformation temperature is at 530℃ and the strain rate is 0.0003s-1, the elongation reaches the maximum value of 1105%, which indicates that at this process parameter the optimal superplasticity is obtained; the strain rate sensitivity index m value is above 0.3 and increases as the temperature going up; when the deformation temperature is at the range of 500-530℃, the m value is above 0.5,the superplastic deformation mechanism of 7B04 Al alloy predominated by grain boundary sliding; the superplastic deformation activation energy Q value is 190kJ/mol which indicates that the superplastic deformation is significantly controlled by the intercrystalline diffusion; the liquid phase will be produced along the grain boundaries of 7B04 Al alloy during superplastic deformation,which can enhance the superplasticity with a moderate amount.
[1] 黄敏,陈轶,李超,等. 7A12-T7352铝合金高温力学性能及断裂行为研究[J]. 航空材料学报,2014,34(1):82-85. HUANG M,CHEN Y,LI C,et al. High temperature mechanical properties and fracture characteristics of 7A12-T7352[J]. Journal of Aeronautical Materials,2014,34(1):82-85.
[2] 佘欢,疏达,储威,等. Fe和Si杂质元素对7XXX系高强航空铝合金组织及性能的影响[J]. 材料工程,2013,(6):92-98. SHE H,SHU D,CHU W,et al. Effects of Fe and Si impurities on the microstructure and properties of 7XXX high strength aircraft aluminum alloys[J]. Journal of Materials Engineering,2013,(6):92-98.
[3] 姬浩. 7000系高强铝合金的发展及其在飞机上的应用[J]. 航空科学技术,2015,26(6):75-78. JI H. Development and application of 7000 high strength aluminum alloys on airplane [J]. Aeronautical Science & Technology,2015,26(6):75-78.
[4] 刘昌斌,夏长清,戴晓元. 高强高韧铝合金的研究现状及发展趋势[J]. 矿冶工程,2003,23(6):74-82. LIU C B,XIA C Q,DAI X Y. Present states of research and developing trends of high strength and high toughness aluminum alloy[J]. Mining and Metallurgical Engineering,2003,23(6):74-82.
[5] 谢优华,陆 政,戴圣龙. Al-6Mg-0.2Sc铝合金高温力学行为研究[J]. 材料工程,2007,(3):49-52. XIE Y H,LU Z,DAI S L. Mechanical behavior of Al-6Mg-0.2Sc aluminum alloys at elevated temperature[J]. Journal of Materials Engineering,2007,(3):49-52.
[6] 宁爱林,曾苏民. 时效制度对7B04铝合金组织和性能的影响[J]. 中国有色金属学报,2004,14(6):922-927. NING A L,ZENG S M. Effects of ageing system on microstructure and mechanical properties of 7B04 aluminium alloy[J]. The Chinese Journal of Nonferrous Metals,2004,14(6):922-927.
[7] 张智慧,左玉婷,刘淑凤. 7B04铝合金板沿厚度方向显微组织、织构及力学性能的研究[J]. 电子显微学报,2011,30(4-5):322-327. ZHANG Z H,ZUO Y T,LIU S F. Study on microstructure, mixture and tensile property of 7B04 aluminium alloy plate along thickness direction [J].Journal of Chinese Electron Microscopy Society,2011,30(4-5):322-327.
[8] 乔志伟. 变形条件对7475铝合金组织和超塑性性能的影响[D]. 湖南:湖南大学,2007. QIAO Z W. The effect of deformation processing on the microstructure and superplastic properties of 7475 Al alloy[D]. Hunan: Hunan university,2007.
[9] TAKAYAMA Y, TOZAMA T, KATO H. Superplasticity and thickness of liquid phase in the vicinity of solidus temperature in a 7475 aluminum alloy[J]. Acta Materialia, 1999, 47(4): 1263-1270.
[10] SMOLEJ A, GNAMUS M, SLACK E. The influence of the thermomechanical processing and forming parameters on superplastic behavior of the 7475 aluminium alloy[J]. Journal of Materials Processing Technology, 2001, 118(1-3): 397-402.
[11] CHEN C L, TAN M J. Effect of grain boundary character distribution (GBCD) on the cavitation behavior during superplastic deformation of Al 7475 [J]. Materials Science & Engineering: A, 2002, 338(1-2): 243-252.
[12] IWASAKI H, MABUCHI M, HIGASHI K. Plastic cavity growth during superplastic flow in AA 7475Al alloy containing a small amount of liquid[J]. Acta Materialia, 2001, 49(12): 2269-2275.
[13] 张林. 喷射成形7475铝合金热处理及超塑性研究[D]. 上海:上海交通大学,2010. ZHANG L. Study on heat treatment process and superplasticity of 7475 alloy by spray forming[D]. Shanghai: Shanghai Jiao Tong University,2010.
[14] WANG T, YIN Z M, SUN Q. Effect of homogenization treatment on microstructure and hot workability of high strength 7B04 aluminium alloy[J]. Transactions of Nonferrous Metals Society of China, 2007, 17(2): 335-339.
[15] LI Z H, XIONG B Q, ZHANG Y A, et al. Effects of the two-step ageing treatment on the microstructure and properties of 7B04 alloy pre-stretched thick plates[J]. Rare Metals, 2007, 26(3): 193-199.
[16] LI Z H, XIONG B Q, ZHANG Y A, et al. Microstructural evolution of aluminum alloy 7B04 thick plate by various thermal treatments[J]. Transactions of Nonferrous Metals Society of China, 2008, 18(1): 40-45.
[17] GAO F H, LI N K, TIAN N, et al. Overheating temperature of 7B04 highstrength aluminum alloy[J]. Transactions of Nonferrous Metals Society of China, 2008, 18(2): 321-326.
[18] 景武,赵怿,许广兴,等. 7B04铝合金薄板成形过程中的退火工艺优化[J]. 沈阳理工大学学报,2012,31(2):91-94. JING W,ZHAO Y,XU G X,et al. Optimum annealing process scheme in aluminum alloy 7B04 sheet formation[J]. Journal of Shenyang Ligong University,2012,31(2):91-94.
[19] 李超,万敏,黄霖. 7B04铝合金蠕变过程中析出相的影响因素[J]. 航空材料学报,2009,29(2):13-17. LI C,WAN M,HUANG L. Effect on precipitation phases of 7B04 aluminum alloy during creep process[J]. Journal of Aeronautical Materials,2009,29(2):13-17.
[20] LIN D, SUN F. Superplasticity in a large-grained TiAl alloy[J]. Intermetallics, 2004, 12(7): 875-883.
[21] 张凯锋,尹德良,王国峰,等. 热轧AZ31镁合金超塑变形中的微观组织演变及断裂行为[J]. 航空材料学报,2005,25(1):5-10. ZHANG K F,YIN D L,WANG G F,et al. Microstructure evolution and fraction behavior in superplastic deformation of hot-rolled AZ31 Mg alloy[J]. Journal of Aeronautical Materials,2005,25(1):5-10.
[22] CHEN K C, TAN M J. Cavity growth and filament formation of superplastically deformed Al 7475 alloy[J]. Materials Science & Engineering: A, 2001, 298(1): 235-244.
[23] 张福全,乔志伟,陈振华,等. 微量液相与7475铝合金的超塑性变形[J].矿冶工程,2007,27(4):71-73. ZHANG F Q,QIAO Z W,CHEN Z H,et al. Effects of small amount of liquid on the superplasicity deformation of 7475 aluminium alloy[J]. Mining and Metallurgical Engineering,2007,27(4):71-73.
[24] 许晓静. 微量液相与铝基复合材料高应变速率超速性[J]. 宇航材料工艺,1999,29(5):41-43. XU X J. Role of liquid in high strain rate superplasticity of aluminum matrix composites[J]. Aerospace Materials and Technology,1999,29(5):41-43.
2017, Vol. 45 
