INVESTIGATION ON CHROMIUM-FREE CONVERSIONCOATING ON AZ91D MAGNESIUM ALLOY

J Chin Soc Corr Pro

2007, Vol. 27

Issue (1): 17-22 DOI:

Research Report

Current Issue | Archive | Adv Search

INVESTIGATION ON CHROMIUM-FREE CONVERSIONCOATING ON AZ91D MAGNESIUM ALLOY

;;;

华中科技大学

Download:

PDF(1747KB)
Export: BibTeX | EndNote (RIS)

Abstract A chromium-free conversion coating treatment whose solution contains phosphate acid、 nitrate compound and accelerator was developed for magnesium alloy.The morphology of conversion was observed using AFM and SEM.The AFM results showed the surface of coating is smooth and slightly wavy.The structure and the composition were analyzed by using EDS and XRD.The EDX results indicated that the compositions of the coating were mainly compounds of Mg,Al,Mn，P，Ca and O.XRD result showed that coating layer contains amorphous materials and a small quantity of Ca0.965Mg2Al6O27,Mn5.64P3,ZnAl2O4 and (Mg0.66Al0.34)(Al0.83Mg0.17)2O4 crystalline compounds.Electrochemical impedance spectroscopy (EIS) and electrochemical polarisation was utilized to study the coating immersion in NaCl slution.The EIS and electrochemical polarisation results demonstrated that the reason for pitting corrosion of conversion coating is that dissolution at the chlorine anion absorbed area is higher than that of non-absorbed area.

Key words: AZ91D Mg alloys chromium-free conversion coating impedance spectroscopy pitting corrosion

Received: 08 August 2005

ZTFLH:

TG174.44

	Service

	E-mail this article
	Add to citation manager
	E-mail Alert
	RSS
	（）
	Articles by authors

Cite this article:

;. INVESTIGATION ON CHROMIUM-FREE CONVERSIONCOATING ON AZ91D MAGNESIUM ALLOY. J Chin Soc Corr Pro, 2007, 27(1): 17-22 .

URL:

https://www.jcscp.org/EN/ OR https://www.jcscp.org/EN/Y2007/V27/I1/17

[1]Rudd A L,Breslin C B,Mansfeld F.The corrosion protection affor-ded by rare earth conversion coatings applied to magnesium[J].Corros.Sci.,2000,42:257-288
[2]Yfantis A,Paloumpa I,Schmei D,et al.Novel corrosion-resistantfilms for Mg alloys[J].Surf.Coat.Tech.,2002,151-152:400-404
[3]Gonzalez-Nunez M A,Nunez-Lopez C A.A non-chromate con-version coating for magnesium alloys and magnesium-based metalmatrix composites[J].Corros.Sci.,1995,37(11):1763-1765
[4]Wu S S,Zhao M,Luo J R,et al.Properties of conversion coating ofmagnesium alloys by a phosphate-permanganate solution[J].Ma-ter.Sci.Forum,2005,488-489:665-667
[5]Cao C N,Zhang J Q.An Introduction to Electrochemical ImpedanceSpectroscopy[M].Beijing:Science Press,2002(曹楚南,张鉴清.电化学阻抗谱导论[M].北京:科学出版社,2002)
[6]Coverdale R T,Christensen B J,Jennings H M.Interpretation of im-pedance spectroscopy of cement paste via computer modeling[J].J.Mater.Sci.,1995,30:712-715
[7]Pye E L,Golestaneh K.Equivalent electronic circuits computer gen-erated from alternating-current impedance data[A].ComputerModeling in Corrosion[C].Philadelphia4:ASTM,1992,5-16
[8]Conde A,de Damborenea J J.Electrochemical impedance spectrosco-py for studying the degradation of enamel coating[J].Corros.Sci.,2002,44(11):1555-1567
[9]Udhayan R,Bhatt D P.On the corrosion behaviour of magnesiumandits alloys using electrochmeical techniques[J].J.Power Sources,1996,63:103-107
[10]Darowick K.Corrosion rate measurements by non-linear electro-chemical impedance spectroscopy[J].Corros.Sci.,1995,37(6):913-915
[11]Juzelinas E,Leinartas K,Frbeth W,et al.Study of initial stages ofAl-Mg alloy corrosion in water,chloride and Cu(Ⅱ)environmentby a scanning Kelvin probe[J].Corros.Sci.,2003,45:1939-1941
[12]Song G L,Atrens A,Dargusch M.Influence of microstructure on thecorrosion of diecast AZ91D[J].Corros.Sci.,1999,41:249-273

[1]	RAN Dou, MENG Huimin, LIU Xing, LI Quande, GONG Xiufang, NI Rong, JIANG Ying, GONG Xianlong, DAI Jun, LONG Bin. Effect of pH on Corrosion Behavior of 14Cr12Ni3WMoV Stainless Steel in Chlorine-containing Solutions[J]. 中国腐蚀与防护学报, 2021, 41(1): 51-59.
[2]	ZHANG Hao, DU Nan, ZHOU Wenjie, WANG Shuaixing, ZHAO Qing. Effect of Fe³⁺ on Pitting Corrosion of Stainless Steel in Simulated Seawater[J]. 中国腐蚀与防护学报, 2020, 40(6): 517-522.
[3]	YU Haoran, ZHANG Wenli, CUI Zhongyu. Difference in Corrosion Behavior of Four Mg-alloys in Cl^--NH₄⁺-NO₃^- Containing Solution[J]. 中国腐蚀与防护学报, 2020, 40(6): 553-559.
[4]	DAI Mingjie, LIU Jing, HUANG Feng, HU Qian, LI Shuang. Pitting Corrosion Behavior of X100 Pipeline Steel in a Simulated Acidic Soil Solution under Fluctuated Cathodic Protection Potentials Based on Orthogonal Method[J]. 中国腐蚀与防护学报, 2020, 40(5): 425-431.
[5]	ZHANG Xin, YANG Guangheng, WANG Zehua, CAO Jing, SHAO Jia, ZHOU Zehua. Corrosion Behavior of Al-Mg-RE Alloy Wires Subjected to Different Cold Drawing Deformation[J]. 中国腐蚀与防护学报, 2020, 40(5): 432-438.
[6]	HE San, SUN Yinjuan, ZHANG Zhihao, CHENG Jie, QIU Yunpeng, GAO Chaoyang. Corrosion Behavior of 20# Steel in Alkanolamine Solution Mixed with Ionic Liquid Containing Saturated CO₂[J]. 中国腐蚀与防护学报, 2020, 40(4): 309-316.
[7]	LI Qing, ZHANG Deping, WANG Wei, WU Wei, LU Lin, AI Chi. Evaluation of Actual Corrosion Status of L80 Tubing Steel and Subsequent Electrochemical and SCC Investigation in Lab[J]. 中国腐蚀与防护学报, 2020, 40(4): 317-324.
[8]	Yu LI,Lei GUAN,Guan WANG,Bo ZHANG,Wei KE. Influence of Mechanical Stresses on Pitting Corrosion of Stainless Steel[J]. 中国腐蚀与防护学报, 2019, 39(3): 215-226.
[9]	Xia WANG,Shuaifei REN,Daixiong ZHANG,Huan JIANG,Yue GU. Inhibition Effect of Soybean Meal Extract on Corrosion of Q235 Steel in Hydrochloric Acid Medium[J]. 中国腐蚀与防护学报, 2019, 39(3): 267-273.
[10]	Bo DA,Hongfa YU,Haiyan MA,Zhangyu WU. Equivalent Electrical Circuits Fitting of Electrochemical Impedance Spectroscopy for Rebar Steel Corrosion of Coral Aggregate Concrete[J]. 中国腐蚀与防护学报, 2019, 39(3): 260-266.
[11]	Bo DA,Hongfa YU,Haiyan MA,Zhangyu WU. Influence of Inhibitors on Reinforced Bar Corrosion of Coral Aggregate Seawater Concrete[J]. 中国腐蚀与防护学报, 2019, 39(2): 152-159.
[12]	Xiuling LAN,Guangming LIU,Jiesheng ZHOU,Zhilei LIU,Shusen PENG,Maodong LI. Preparation and Properties of Organosilicone/SiO₂Hybrid Sol Modified Acrylic Resin[J]. 中国腐蚀与防护学报, 2018, 38(6): 601-606.
[13]	Peichang DENG, Quanbing LIU, Ziyun LI, Gui WANG, Jiezhen HU, Xie WANG. Corrosion Behavior of X70 Pipeline Steel in the Tropical Juncture Area of Seawater-Sea Mud[J]. 中国腐蚀与防护学报, 2018, 38(5): 415-423.
[14]	Zhimin FAN, Jin YU, Yingwei SONG, Dayong SHAN, En-Hou HAN. Research Progress of Pitting Corrosion of Magnesium Alloys[J]. 中国腐蚀与防护学报, 2018, 38(4): 317-325.
[15]	Sanxi DENG, Xiaoyu YAN, Ke CHAI, Jinyi WU, Hongwei SHI. *Effect of Pseudomonas* sp. on Decomposition and Anticorrosion Behavior of Polysiloxane Varnish Coating**[J]. 中国腐蚀与防护学报, 2018, 38(4): 326-332.

No Suggested Reading articles found!

Viewed

Full text

Abstract

Cited

Shared

Discussed