|
|
|
| SYNERGETIC EFFECT OF Mg2Si AND Si PARTICLES ON INTERGRANULAR CORROSION OF Al-Mg-Si ALLOYS THROUGH MULTI-ELECTRODE COUPLING SYSTEM |
| LI Chaoxing1; LI Jinfeng1;2; BIRBILIS Nick3; JIA Zhiqiang1; ZHENG Ziqiao1;2 |
1. School of Materials Science and Engineering; Central South University; Changsha 410083
2. Key Laboratory of Nonferrous Metal; Materials Science and Engineering;Ministry of Education; Central South University; Changsha 410083
3. ARC Centre of Excellence for Design in Light Metals; Department of Materials Engineering;Monash University; 3800. Australia |
|
|
|
|
Abstract The potentiodynamic scanning curves and the electrochemical coupling behaviors of constituent phases at the grain boundary of Al-Mg-Si alloy were investigated. The corrosion mechanism of Al-Mg-Si alloys different ratio of Mg to Si was analyzed. The results show that the Si particle is cathodic to the Al-base and causes the anodic dissolution of Al-base at its adjacent periphery. At the beginning, the precipitate of Mg2Si is anodic to the Al-base and corrosion occurs on its surface. However, during its corrosion process, its potential moves to a positive direction with immersion time increasing, due to the preferential dissolution of Mg and the enrichment of Si, which makes Mg2Si become cathodic to Al- base and leads to the anodic dissolution of the Al-base at its adjacent periphery at a later stage. At the grain boundary of Al-Mg-Si alloys with a ratio of Mg to Si higher than 1.73, the Mg-and-Si contained precipitates are distributed discontinuously, resulting in that they are not sensitive to intergranular corrosion. There exist Mg-and-Si-contained precipitates and Si particles at the grain boundary of Al-Mg-Si alloys with a ratio of Mg to Si less than 1.73, corrosion occurs firstly on the surface of Mg2Si. Meanwhile, the Si particle leads to the great anodic dissolution of the precipitate-free-zone(PFZ) at its adjacent periphery. The Si particle also accelerates the preferential dissolution of Mg in Mg2Si precipitate, expediting the polarity transformation between Mg2Si and the PFZ. As a result, the corrosion development along the PFZ at the adjacent of Mg2Si particle is enhanced.
|
|
Received: 17 December 2008
|
|
|
|
Corresponding Authors:
LI Jinfeng
E-mail: lijinfeng@mail.cus.edu.cn
|
Cite this article:
LI Chaoxing; LI Jinfeng; BIRBILIS Nick; JIA Zhiqiang; ZHENG Ziqiao. SYNERGETIC EFFECT OF Mg2Si AND Si PARTICLES ON INTERGRANULAR CORROSION OF Al-Mg-Si ALLOYS THROUGH MULTI-ELECTRODE COUPLING SYSTEM. J Chin Soc Corr Pro, 2010, 30(2): 107-113.
URL:
https://www.jcscp.org/EN/ OR https://www.jcscp.org/EN/Y2010/V30/I2/107
|
| [1] Osaki S H, Kinoshita K, Naganuma D.Intergranular corrosion and SCC properties of Al-Mg-Si alloy sheets [J]. J. Inst. Light Met., 2003, 53(4): 157-162
[2] Es-Said O S,Frazier W E, Lee E W. The effect of retrogression and reaging on the properties of the 7249 aluminum alloy [J]. JOM. 2003, (1): 45-48
[3] Zheng Z Q, Li H Y, Mo Z M. Retrogression and reaging treatment of a 7055 type aluminum alloy [J]. Chin. J. Nonferrous Met., 2001, 11(5): 771-775
(郑子樵, 李红英, 莫志民. 一种7055型铝合金的RRA处理 [J]. 中国有色金属学报,2001, 11(5): 771-775)
[4] Ru J G, Yi L N,Zhang L S. A study of the ultra high strength aluminium alloy heat treatment process [J]. J.Mater Eng., 1999, (2): 37-39
(汝继刚, 伊琳娜, 张禄山. 超高强铝合金热处理工艺研究 [J]. 材料工程, 1999, (2): 37-39)
[5] Pzark J K, Ardell A J. Microstructures of the commercial 7075 Al,alloy in the T651 and T7 tempers [J]. Metall. Trans., 1983, 14: 1957-1965
[6] Meng Z F, Zheng Y, Long H W, et al, Hardness changes of Al-Zn-Mg alloy during retrogression and reaging [J]. Acta Metall. Sin., 1997, 33(5): 479-484
(孟昭富, 郑勇, 龙厚文等. 再时效-回归-再时效处理过程中Al-Zn-Mg 系合金硬度的改变 [J]. 金属学报, 1997, 33(5): 479-484)
[7] Zeng Y, Yin Z M, Zhu Y Z, et al. Effect of RRA on microstructure and properties of new type ultra high strength aluminum alloy [J]. Chin. J. Nonferrous Met., 2004, 14(7): 1188-1194
(郑渝, 尹志民, 朱远志等. RRA处理对超高强铝合金微观组织和性能的影响 [J]. 中国有色金属学报, 2004, 14(7): 1188-1194)
[8] Li J F, Peng Z W, Li C X, et al. Mechanical properties, corrosion behaviors and microstructures of 7075 aluminium ally with various aging treatements [J]. Trans.Nonferrous Met. Soc. China, 2008, 18: 755-762
[9] Wang Z T, Tian R Z. Handbook of Aluminum Alloy and Fabrication (2nd) [M]. ChangSha: Central South University Press, 2000: 132
(王祝堂, 田荣璋. 铝合金及其加工手册（第二版）[M]. 长沙：中南大学出版社，2000：132)
[10] Birbilis N, Buchheit R G. Electrochemical characteristics of intermetallic phases in aluminum alloys [J]. J.Electrochem. Soc., 2005, 152(4), B140-B151
[11] Li J F, Zheng Z Q, Li S C, et al. Simulation study on function mechanism of some precipitates in localized corrosion of Al alloys [J]. Corros. Sci., 2007, 49: 2436-2449
[12] Buchheit R G, Grant R P, Hlava P F, et al. Local dissolution phenomena associated with S phase(Al2CuMg) particles in aluminum alloy 2024-T3 [J]. J. Electrochem. Soc., 1997, 144(8): 2621-2628
[13] Shao M H, Fu Y, Hu R G, et al. A study on pitting corrosion of aluminum alloy 2024-T3 by scanning microreference electrode technique [J]. Mater. Sci. Eng., 2003, A344: 323-327
[14] Li J F, Zheng Z Q, Jiang N, et al. Study on localized corrosion mechanism of 2××× series Al alloy containing S(Al2CuMg) and θ′(Al2Cu) precipitates in 4.0% NaCl solution at pH=6.1 [J]. Mater. Chem.Phys., 2005, 91(2-3): 325-329
[15] Mizuno K, Nylund A, Olefjord I. Surface reactions during pickling of an aluminum-magnesium-silicon alloy in phosphoric acid [J]. Corros. Sci., 2001, 43(2): 381-396
[16] Li J F, Zheng Z Q, Ren W D, et al. Simulation on function mechanism of T1(Al2CuLi) precipitate in localized corrosion of Al-Cu-Li alloys [J]. Trans. Nonferrous Met. Soc. China,2006, 16: 1268-1273
[17] Wang Z H, Zhou G Y. Controlling composition of 6063 aluminium alloy based on production process and material application [J]. Light Alloy Fabr. Technol., 2000, (12): 31-32
(王宗和, 周光永. 根据工艺和材料用途控制6063铝合金的成分 [J]. 轻合金加工技术, 2000, (12): 31-32 |
| No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|
