Fatigue Properties and Fracture Mechanism of Aluminum Alloy with Orifice Chamfer and Pre-corrosion Damage
Song ZHOU1,2, Lei WANG1, Chuang MA1, Lin-qing YANG1, Liang XU1, Li HUI1,*()
1 Key Laboratory of Fundamental Science for National Defense of Aeronautical Digital Manufacturing Process, Shenyang Aerospace University, Shenyang 110136, China 2 Department of Mechanical Engineering and Automation, Northeastern University, Shenyang 110004, China
Fatigue fracture often occurs because of the corrosion damage to aerospace structural aluminum alloy with holes. Fatigue tests of 7075 aluminum alloy of both unchamfered and chamfered double-hole specimens under uncorrosion and 24h pre-corrosion were carried out. The influence of both pre-corrosion damage and orifice chamferer on fatigue properties and the differences of fatigue fracture characteristics were analyzed. The results show that the effect on fatigue life of pre-corrosion damage is significant. Median fatigue lives of both unchamfered and chamfered double-hole specimens under 24h pre-corrosion decrease about 31.74% and 26.92% compared with uncorrosion specimens. The orifice chamferer have a certain effect on fatigue life of both uncorrosion and 24h pre-corrosion specimens, with median fatigue lives decreased about 28.02% and 15.36% compared with unchamfered specimens, the main reason is due to the stress concentration after orifice chamfered, on the other hand, cutting marks lead to pre-damage during the orifice chamfering process which will result in an increase of the fatigue crack initiation sites and the fracture probability.
ZHOU S, XIE L Y, HUI L, et al Influence of shot peening on fatigue life of 2xxx aluminum alloy[J]. Journal of Materials Engineering, 2014, (12): 86- 91.
MA S H, HUI L, ZHOU S, et al Influence of corrosion environments on corrosion fatigue property of pre-corroded aluminum alloy[J]. Journal of Materials Engineering, 2015, 43 (2): 91- 95.
CHEN Y L, BIAN G X, YU D Z Study on fatigue life of pre-corrosion aluminum alloy typical single bolted lap joints[J]. Engineering Mechanics, 2012, 29 (5): 251- 256.
HU B R, MA S J, TONG D H, et al Test methods for determining flaw tolerance value of 7050 aluminum alloy forging[J]. Journal of Aeronautical Materials, 2015, 35 (1): 82- 86.
5
SANKARAN K K, PEREZ R, JATA K V Effects of pitting corrosion on the fatigue behavior of aluminum alloy 7075-T6: modeling and experimental studies[J]. Materials Science and Engineering, 2001, 297 (1): 223- 229.
6
PAO P S, GILL S J, FENG C R On fatigue crack initiation from corrosion pits in 7075-T7351 aluminum alloy[J]. Scripta Materialia, 2000, 43 (5): 391- 396.
HU J L, CHEN Y L, ZHAN D, et al Analysis of corrosion damage and fatigue life based on corrosion image[J]. Acta Aeronautica et Astronautica Sinica, 2010, 31 (1): 131- 135.
ZHANG Y H, LU G Z, CHEN Y L Predicting fatigue life from precorrosion LY12-CZ aluminium test[J]. Acta Aeronautica et Astronautica Sinica, 2005, 26 (6): 779- 782.
9
DUQUESNAY D L, UNDERHILL P R, BRITT H J Fatigue crack growth from corrosion damage in 7075-T6511 aluminum alloy under aircraft loading[J]. International Journal of Fatigue, 2003, 25, 371- 377.
10
DOLLEY E J, LEE B, WEI R P Effect of pitting corrosion on fatigue life[J]. Fatigue and Fracture of Engineering Materials and Structures, 2000, 23 (7): 555- 560.
11
GRUENBERG K M, CRAIG B A, HILLBERRY B M, et al Predicting fatigue life of pre-corrosion 2024-T3 aluminum[J]. International Journal of Fatigue, 2004, 26 (6): 629- 640.
12
GRUENBERG K M, CRAIG B A, HILLBERRY B M, et al Predicting fatigue life of pre-corrosion 2024-T3 aluminum from breaking load tests[J]. International Journal of Fatigue, 2004, 26 (6): 615- 627.
13
MALKI B, BAROUX B Computer simulation of the corrosion pit growth[J]. Corrosion Science, 2005, 47 (1): 171- 182.
14
RAMANA M P, LONG F, MATHEW J P Computational simulation of multi-pit corrosion process in materials[J]. Computational Materials Science, 2008, 41 (3): 255- 265.
15
KIMBERLI J, SACHIN R S, PAUL N C, et al Effect of prior corrosion on short crack behavior in 2024-T3 aluminum alloy[J]. Corrosion Science, 2008, 50 (9): 2588- 2595.
LIU J Z, CHEN B, YE X B, et al Fatigue and crack growth behavior of pre-corrosion aluminum alloy 2024-T62 and its life prediction based on fracture mechanics[J]. Acta Aeronautica et Astronautica Sinica, 2011, 32 (1): 107- 116.