|
|
|
| ELECTROLESS NICKEL PLATING OF MAGNESIUM ALLOY WITH MICROARC OXIDATION PRETREATMENT |
| LI Junming1, XUE Xiaonan2, WANG Aijuan1, MA Anbo1, FU Zhizhao1
|
1. School of Materials Science and Engineering, Xi'an University of Technology,Xi'an 710048
2. CSR Zhuzhou Electric Locomotive Co. Ltd, Zhuzhou, 412001 |
|
|
|
|
Abstract Magnesium alloys after microarc oxidation (MAO) pretreatment were directly electroless Ni plated by using NiSO4 solution, meanwhile, any traditional pretreatment, including alkaline washing, acid washing and activation, etc., was used. The microstructure and composition of nickel layer were characterized. The effect of MAO pretreatment on the thickness, hardness, electrical conductivity and corrosion resistance of nickel layer were investigated. The results indicate that the layer which contains Ni and P is composed of cellular particles. MAO pretreatmely affects the thickness and electrical conductivity of nickel layer significantly. The thickness of nickel layer fastly increases but the sheet resistance of the layer rapidly decreases when the thickness of MAO film increases from 3 to 7 μm. Furthermore, the results of polarization curve test reveal that when the thickness of MAO film is 15 $\mu$m, the corrosion potential of the obtained electroless nickel plated magnesium alloy is the highest, and the corrosion current is the lowest. The results of 48 h salt spray test show that the corrosion resistance of electroless nickel plated magnesium alloy with MAO pretreatment is much higher than that of electroless nickel plated magnesium alloy with traditional pretreatment and magnesium alloy substrate.
|
|
Received: 03 May 2011
|
|
|
|
Corresponding Authors:
LI Junming
E-mail: lijm320@126.com
|
| [1] Iranipour N, Azari K R, Parvini A N. A study on the electroless Ni-P deposition on WE43 magnesium alloy [J]. Surf. Coat.Technol., 2010, 205(7): 2281-2286[2] Huang C A, Lin C K, Yeh Y H. Corrosion behavior of Cr/Cu-coated Mg alloy (AZ91D) in 0.1 M H2SO4 with different concentrations of NaCl [J]. Corros. Sci., 2010, 52(4):1326-1332[3] Zeng L Y, Yang S W, Zhang W, et al. Preparation and characterization of a double-layer coating on magnesium alloy AZ91D [J]. Electrochim. Acta, 2010, 55(9): 3376-3383[4] Duan H P, Du K Q, Yan C W, et al. Electrochemical corrosion behavior of composite coatings of sealed MAO film on magnesium alloy AZ91D [J]. Electrochim. Acta, 2006, 51(14):2898-2908[5] Liu X K, Xiang Y H, Hu W B, et al. Adhesion mechanism of direct electroless nickel coating on magnesium alloys [J]. J. Chin.Soc. Corros. Prot., 2002, 22(4): 233-236 (刘新宽, 向阳辉,胡文彬等. 镁合金化学镀镍层的结合机理 [J]. 中国腐蚀与防护学报, 2002,22(4): 233-236)[6] Zhang W X, He J G, Jiang Z H, et al. Electroless Ni-P layer with a chromium-free pretreatment on AZ91D magnesium alloy [J]. Surf. Coat. Technol., 2007, 201(8): 4594-4600[7] Gray J E, Luan B. Protective coatings on magnesium and its alloys-a critical review [J]. J. Alloy Compd., 2002, 336(1-2):88-113[8] Cui X F, Jin G, Li Q F, et al. Electroless Ni-P plating with a phytic acid pretreatment on AZ91D magnesium alloy [J]. Mater.Chem. Phys., 2010, 121(1-2): 308-313[9] Song Y W, Shan D Y, Han E H. High corrosion resistance of electroless composite plating coatings on AZ91D magnesium alloys [J]. Electrochim. Acta, 2008, 53(5): 2135-2143[10] Gu C D, Lian J S, Li G Y, et al. Electroless Ni-P plating on the AZ91D magnesium alloy [J]. J. Chin. Soc. Corros. Prot., 2005,25(5): 271-274 (谷长栋, 连建设, 李光玉等.AZ91D镁合金的化学镀镍[J]. 中国腐蚀与防护学报, 2005, 25(5): 271-274)[11] Gu C D, Lian J S, Li G Y, et al. Electroless Ni-P plating on AZ91D magnesium alloy from a sulfate solution [J]. J. AlloyCompd., 2005, 391(1-2): 104-109[12] Li J Z, Shao Z C, Zhang X, et al. The electroless nickel-plating on magnesium alloy using NiSO4•6H2O as the main salt [J]. Surf. Coat. Technol., 2006, 200(9): 3010-3015[13] Valova E, Dille J, Armyanov S, et al. Interface between electroless amorphous Ni-Cu-P coatings and Al substrate [J]. Surf.Coat. Technol., 2005, 190(2-3): 336-344[14] Cheong W J, Luan B L, Shoesmith D W. Protective coating on Mg AZ91D alloy-The effect of electroless nickel (EN) bath stabilizers on corrosion behaviour of Ni-P deposit [J]. Corros.Sci., 2007, 49(4): 1777-1798[15] Li J M, Xue X N, Cai H, et al. Preparation and characterization of electroless Ni coating on the surface of MgO with porous structure [J]. Acta Metall. Sin., 2010, 46(9): 1103-1108 (李均明, 薛晓楠, 蔡辉等.多孔结构MgO表面化学镀Ni层的制备与表征 [J]. 金属学报, 2010, 46(9):1103-1108)[16] Jiang X X, Shen W. Theory and Practice of Electroless Plating [M]. Beijing: National Defense Industry Press, 2000 (姜晓霞，沈伟. 化学镀理论与实践 [M]. 北京: 国防工业出版社, 2000)[17] Yang B C, Wang W S. Film Physics and Technology [M].Chengdu: University of Electronic Science and Technology of China Press, 2006 (杨邦朝, 王文生. 薄膜物理与技术[M]. 成都: 电子科技大学出版社, 2006) |
| No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|
