在100-210℃和150-300 MPa的条件下, 研究了Al-5.3Cu-0.8Mg-0.5Ag-0.3Mn-0.15Zr耐热铝合金的蠕变行为, 探讨了时效状态对合金高温性能的影响. 结果表明: 在相同蠕变条件下, 欠时效态合金的稳态蠕变速率远远低于峰时效态合金. 在210℃/200 MPa下, 欠时效态合金的蠕变断裂时间为75 h, 而峰时效态合金的蠕变断裂时间仅为21 h. 蠕变过程中, 合金中的析出相长大. 峰时效态合金中析出相尺寸的增大速率高于欠时效态合金. 欠时效态合金中还发生了动态析出, 这些细小的析出相在蠕变过程中阻碍了位错的运动, 使得合金蠕变速率降低. 在100-150℃下合金的稳态蠕变速率保持在较低水平. 当温度升高到180℃时, 合金的稳态蠕变速率急剧增大. 合金稳态蠕变速率随着蠕变温度的升高和应力的提高均有增大趋势, 3者之间的关系可用一本构方程来表示, 其表观激活能为102 kJ/mol.
The creep behaviors of heat--resistant alloy Al-5.3Cu-0.8Mg-0.5Ag-0.3Mn-0.15Zr (Al-Cu-Mg-Ag) were studied in a temperature range of 100-210℃ and a load range of 150-300 MPa, and the effect of aging on the properties of Al-Cu-Mg-Ag alloy at elevated temperatures was also investigated. The results show that the steady creep rate of the under-aged alloy is much lower than that of the peak--aged alloy at the same creep conditions. The creep fracture time is 75 h for the under-aged Al-Cu-Mg-Ag alloy at 210℃/200 MPa, while that for the peak-aged alloy is only 21 h. The precipitates grow gradually during the creep process and the growth rate in the peak-aged alloy is higher than that in the under-aged alloy. Dynamic precipitation happened in the under-aged alloy. The fine precipitates inhibite the motion of the dislocations during the creep, which leads to lower creep deformation rate compared to the peak-aged alloy. The steady creep rates of the under-aged Al-Cu-Mg-Ag alloy at 100-150℃ keep a relatively lower level, but increases to a high level when the creep temperature increased to 180℃. The steady creep rate increased with increasing temperature or stress, which can be described by a constitutive equation with an apparent activation energy of 102 kJ/mol.
[1] Sukumaran K, Ravikumar K K, Pillai S G K, Rajan T P D, Ravi M, Pillai R M, Pai B C. Mater Sci Eng, 2008; A490: 235
[2] Naga R P, Srinivasa R K, Reddy G M, Kamaraj M, Prasad R K. Mater Sci Eng, 2007; A464: 192
[3] Wang J, Yi D, Su X, Yin F. Mater Charact, 2008; 59: 965
[4] Yu K, Li W, Li S, Zhao J. Mater Sci Eng, 2004; A368: 88
[5] Chang C H, Lee S L, Lin J C, Yeh M S, Jeng R R. Mater Chem Phys, 2005; 91: 454
[6] Xiao D H, Wang J N, Ding D Y, Chen S P. J Alloys Compd, 2002; 343: 77
[7] Bakavos D, Prangnell P B, Bes B, Eberl F. Mater Sci Eng, 2008; A491: 214
[8] Somi R A. Mater Des, 2008; 29: 763
[9] Lumley R N, Morton A J, Polmear I J. Acta Mater, 2002; 50: 3597
[10] Yan J L, Sun Y S, Xue F, Tao W J. Acta Metall Sin, 2008; 44: 1354
(晏井利, 孙扬善, 薛烽, 陶卫建. 金属学报, 2008; 44: 1354)
[11] Spigarelli S, Evangelista E, Cucchieri S. Mater Sci Eng, 2004; A387–389: 702
[12] Qi Y H, Guo J T, Cui C Y. Acta Metall Sin, 2001; 37: 957
(齐义辉, 郭建亭, 崔传勇. 金属学报, 2001; 37: 957)
[13] Kermanidis A T, Zervaki A D, Haidemenopoulos G N, Pantelakis Sp G. Mater Des, 2010; 31: 42
[14] Das G, Das M, Ghosh S, Dubey P, Ray A K. Mater Sci Eng, 2010; A527: 1590
[15] Xia Q K, Liu Z Y, Li Y T. Trans Nonferrous Met Soc China, 2008; 18: 789
[16] Seeger A T. Naturforschung, 1956; 9: 758
[17] Sha G Y, Han E H, Yu T, Xu Y B, Liu L, Gao G Z. Acta Metall Sin, 2003; 39: 1025
(沙桂英, 韩恩厚, 于 涛, 徐永波, 刘 路, 高国忠. 金属学报, 2003; 39: 1025)
[18] Li B Q, Wawner F E. Acta Mater, 1998; 46: 5483
[19] Mukherjee A K, Bird J E, Dorn J E. Trans ASM, 1969; 62: 155
