-
摘要:
高低温裂纹扩展性能是航空金属结构损伤容限设计的前提，为此，试验测定了3种系列的6种航空铝合金材料（2024-T351、2397-T8、6061-T651、7050-T7451、7050-T7452和7475-T761）在5种温度环境（-70、-54、25、125和150℃）下的裂纹扩展性能，观测了试验现象，并进行了性能对比分析和疲劳断口扫描电子显微镜（SEM）分析，研究了温度对航空铝合金材料裂纹扩展性能的影响机制，获得了具有工程参考价值的结果与结论：与25℃相比，低温下裂纹扩展阻力系数的对数值降低7%~15%，而高温下却增大5%~23%；低温下裂纹扩展指数增大7%~21%，而高温下却减少5%~34%；氢脆效应和高温氧化作用是导致裂纹扩展速率随温度升高而加快的主要原因。
-
关键词:
- 铝合金 /
- 裂纹扩展 /
- 疲劳 /
- 温度 /
- 扫描电子显微镜 (SEM)
Abstract:Fatigue properties on crack propagation rate at low and elevated temperatures are the precondition of damage tolerance design for aviation metallic structures. Therefore, in order to determine fatigue properties on crack propagation rate, fatigue tests were performed on six categories of aluminum alloys (i.e. 2024-T351, 2397-T8, 6061-T651, 7050-T7451, 7050-T7452, 7475-T761) at five kinds of temperatures (-70℃, -54℃, 25℃, 125℃, 150℃) under constant amplitude loading, and fatigue crack propagation properties were determined and the comparisons between fatigue properties on crack propagation rate at different temperatures were carried out. The mechanisms of temperature effect on crack propagation rate were deduced from fractographic studies by using scanning election microscope (SEM). The results show that, compared with the situation at 25℃, logarithmic crack propagation resistance coefficient decreases by 7% to 15% at low temperature, but increases by 5% to 23% at elevated temperature; crack propagation exponent increases by 7% to 21% at low temperature, but decreases by 5% to 34% at elevated temperature, compared with the situation at 25℃; hydrogen embrittlement and oxidation effects are likely to be the main reasons for more rapid crack propagation with the increasing temperature.
-
Key words:
- aluminum alloy /
- crack propagation /
- fatigue /
- temperature /
- scanning election microscope (SEM)
-
表 1 铝合金材料的力学性能
Table 1. Mechanical properties of aluminum alloy materials
材料 E/GPa σb/MPa σs/MPa δ/% 2024-T351 72.4 473 364 18.0 2397-T8 70.0 472 421 9.5 6061-T651 71.0 311 246 14.7 7050-T7451 70.3 510 455 9.0 7050-T7452 70.5 475 399 11.1 7475-T761 70.5 526 482 13.3 
下载: 导出CSV
表 2 裂纹扩展速率da/dN-ΔK参数值
Table 2. Parameter values of crack propagation rate da/dN-ΔK
材料 T/℃ C m 2024-T351 125 9.93×10-10 3.45 25 3.56×10-11 4.08 -54 1.17×10-12 4.87 2397-T8 150 4.60×10-9 3.07 25 7.61×10-10 3.51 -70 3.52×10-11 4.22 6061-T651 150 1.24×10-10 4.23 25 3.10×10-11 4.48 -70 5.63×10-12 4.80 7050-T7451 150 9.02×10-10 3.60 25 2.35×10-10 3.94 7050-T7452 150 1.31×10-8 3.01 25 6.66×10-11 4.54 7475-T761 125 6.67×10-9 3.45 25 1.90×10-9 3.75 -54 3.71×10-10 4.15
下载: 导出CSV
-
[1] JAMES T B, VIPUL K G, SEAN R A, et al.Effect of low temperature on fatigue crack formation and microstructure-scale propagation in legacy and modern Al-Zn-Mg-Cu alloys[J].International Journal of Fatigue, 2013, 55:268-275. doi: 10.1016/j.ijfatigue.2013.06.025 [2] 张福泽, 叶序彬, 宋钧, 等.在25℃和-40℃环境下的三种航空材料的裂纹扩展品质研究[J].航空学报, 2007, 28(3):593-595. http://www.cnki.com.cn/Article/CJFDTOTAL-HKXB200703019.htmZHANG F Z, YE X B, SONG J, et al.Study on crack growth behaviors of three kinds of aeronautical materials at 25℃ and-40℃[J].Acta Aeronautica et Astronautica Sinica, 2007, 28(3):593-595(in Chinese). http://www.cnki.com.cn/Article/CJFDTOTAL-HKXB200703019.htm [3] FASSINA P, BRUNELLA M, LAZZARI L, et al.Effect of hydrogen and low temperature on fatigue crack propagation of pipeline steels[J].Engineering Fracture Mechanics, 2013, 103:10-25. doi: 10.1016/j.engfracmech.2012.09.023 [4] FRANCK A T G, DANIEL L, ALEXANDRE B, et al.Effect of extrusion aspect ratio and test temperatures on fatigue crack propagation behavior of a 2099-T83 Al-Li alloy[J].International Journal of Fatigue, 2014, 59:244-253. doi: 10.1016/j.ijfatigue.2013.08.013 [5] DING J, HALL R, BYRNE J.Effects of stress ratio and temperature on fatigue crack propagation in a Ti-6Al-4V alloy[J].International Journal of Fatigue, 2005, 27(10-12):1551-1558. doi: 10.1016/j.ijfatigue.2005.06.007 [6] 宋千光, 赵彬, 耿小亮, 等.温度和应力比对航空铝合金疲劳裂纹扩展规律的影响及其机理[J].材料科学与工程学报, 2015, 32(2):157-162. http://www.cnki.com.cn/Article/CJFDTOTAL-CLKX201502003.htmSONG Q G, ZHAO B, GENG X L, et al.Effect of stress ratio and temperature on the fatigue crack growth behavior of aerometal and study of the mechanism[J]. Journal of Materials Science and Engineering, 2015, 32(2):157-162(in Chinese). http://www.cnki.com.cn/Article/CJFDTOTAL-CLKX201502003.htm [7] 吴欢, 赵永庆, 曾卫东, 等.不同温度下Ti40合金的疲劳裂纹扩展行为[J].稀有金属材料与工程, 2008, 37(8):1403-1406. http://www.cnki.com.cn/Article/CJFDTOTAL-COSE200808021.htmWU H, ZHAO Y Q, ZENG W D, et al.Fatigue crack propagation behavior of Ti40 alloy at different temperatures[J].Rare Metal Materials and Engineering, 2008, 37(8):1403-1406(in Chinese). http://www.cnki.com.cn/Article/CJFDTOTAL-COSE200808021.htm [8] ADAIR B S, JOHNSON W S, ANTOLOVICH S D, et al.Crystall-ographic orientation and temperature effects on the fatigue crack propagation rate and resulting fracture surface morphology in PWA1484 single crystal superalloy[J].Engineering Materials & Structures, 2015, 38(1):56-68. https://www.researchgate.net/publication/264806372_Crystallographic_orientation_and_temperature_effects_on_the_fatigue_crack_growth_rate_and_resulting_fracture_surface_morphology_in_PWA1484_single_crystal_superalloy [9] 熊缨, 陈冰冰, 郑三龙, 等.16MnR钢在不同条件下的疲劳裂纹扩展规律[J].金属学报, 2009, 45(7):849-855. http://www.cnki.com.cn/Article/CJFDTOTAL-JSXB200907014.htmXIONG Y, CHEN B B, ZHENG S L, et al.Study on fatigue crack growth behavior of 16MnR steel under different conditions[J].Metallurgica Sinica, 2009, 45(7):849-855(in Chinese). http://www.cnki.com.cn/Article/CJFDTOTAL-JSXB200907014.htm [10] SHAH M, MABRU C, REZAI-ARIA F.Characterisation of the surface damage of X38CrMoV5(AISI H11) tool steel at room temperature and 600℃[J].Fatigue & Fracture of Engineering Materials & Structures, 2015, 38(6):742-754. https://www.researchgate.net/profile/Masood_Shah4/publication/271081236_Characterisation_of_the_surface_damage_of_X38CrMoV5_AISI_H11_tool_steel_at_room_temperature_and_600_C/links/5500081a0cf204d683b2c152.pdf?origin=publication_detail [11] 钟警, 贾敏, 范春平, 等.2050铝合金的疲劳裂纹扩展行为研究[J].稀有金属材料与工程, 2014, 43(8):1944-1950. http://www.cnki.com.cn/Article/CJFDTOTAL-COSE201408030.htmZHONG J, JIA M, FAN C P, et al.Fatigue crack propagation behavior of 2050 aluminum alloy[J].Rare Metal Materials and Engineering, 2014, 43(8):1944-1950(in Chinese). http://www.cnki.com.cn/Article/CJFDTOTAL-COSE201408030.htm [12] 郑子樵, 孙晓旭, 陈圆圆, 等.一种Al-Cu-Mg-Zr合金的疲劳裂纹扩展行为研究[J].稀有金属材料与工程, 2010, 39(6):975-979. http://www.cnki.com.cn/Article/CJFDTOTAL-COSE201006010.htmZHENG Z Q, SUN X X, CHEN Y Y, et al.Fatigue crack propagation behavior of Al-Cu-Mg-Zr alloy[J].Rare Metal Materials and Engineering, 2010, 39(6):975-979(in Chinese). http://www.cnki.com.cn/Article/CJFDTOTAL-COSE201006010.htm [13] 宫玉辉, 刘铭, 张坤, 等.不同腐蚀环境对7475-T7351铝合金疲劳性能及裂纹扩展速率的影响[J].材料工程, 2010(9):71-73. http://www.cnki.com.cn/Article/CJFDTOTAL-CLGC201009017.htmGONG Y H, LIU M, ZHANG K, et al.Effects of different corrosion environments on fatigue property and crack growth rate in 7475-T7351 aluminum alloy[J].Journal of Materials Engineering, 2010(9):71-73(in Chinese). http://www.cnki.com.cn/Article/CJFDTOTAL-CLGC201009017.htm [14] KUJAWSKI D.Environmental crack propagation behavior affected by thickness/geometry constraint[J].Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science, 2013, 44A (3):1340-1352. doi: 10.1007/s11661-012-1507-8 [15] WANG Y L, PAN Q L, WEI L L.Fracture toughness and fatigue crack propagation analysis of 7050-T7451 alloy thick plate with different thicknesses[J].Journal of Central South University, 2014, 21(8):2977-2983. doi: 10.1007/s11771-014-2265-0 [16] CARPINTERI A, BRIGHENTI R, VANTADORI S, et al.Static crack extension prediction in aluminium alloy at low temperature[J].Engineering Fracture Mechanics, 2008, 75(3):510-525. http://www.sciencedirect.com/science/article/pii/S0013794407002391 [17] HATAMLEH O, HILL M, FORTH S, et al.Fatigue crack propa-gation performance of peened friction stir welded 2195 aluminum alloy joints at elevated and cryogenic temperatures[J].Materials Science & Engineering A, 2009, 519:61-69. http://www.sciencedirect.com/science/article/pii/S0921509309005498 [18] American Society for Testing Materials International. Standard test method for measurement of fatigue crack propagation rates:ASTM E647-11[S].West Conshohocken:ASTM International, 2011. [19] GASQUE C, CHRISTINE S B, PETIT J, et al.Fatigue crack propagation in an aluminum alloy at 223K[J].Scripta Materialia, 2005, 53(12):1333-1337. doi: 10.1016/j.scriptamat.2005.08.036 [20] SAHU V K, ANIL KUMAR J K S, MOHANTY J R, et al.Effect of low-temperature overload on fatigue crack propagation retardation and prediction of post overload fatigue life[J].Aerospace Science and Technology, 2014, 33(1):100-106. doi: 10.1016/j.ast.2014.01.005 [21] 钟群鹏, 赵子华.断口学[M].北京:高等教育出版社, 2006:267.ZHONG Q P, ZHAO Z H. Fractography[M].Beijing:Higher Education Press, 2006:267(in Chinese). [22] 熊峻江.飞行器结构疲劳与寿命设计[M].北京:北京航空航天大学出版社, 2004:128.XIONG J J.Fatigue life design for aircraft structure[M].Beijing:Beihang University Press, 2004:128(in Chinese). -
下载:
点击查看大图
计量
- 文章访问数: 942
- HTML全文浏览量: 83
- PDF下载量: 1436
- 被引次数: 0
