JSEMAT  Vol.1 No.3 , October 2011
Electrochemical Characterization of Plasma Sprayed Alumina Coatings
Abstract: Open circuit potential (OCP), potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) were employed to characterize the corrosion behavior of plasma-sprayed alumina-coated mild steel in 3.5 wt% NaCl solu-tion. Alumina-coated steel showed higher OCP and lower corrosion current (icorr.) compared with the steel substrate. However, localized corrosion probably occurs at the coat/steel interface when immersed in the corrosive media. The reason for that is the penetration of corrosive solution into the steel surface through the pores of accumulated alumina layers. The corrosion products (mainly iron oxides) accumulate inside the pores and on the coating surface. The presence of iron oxide slightly improved the corrosion resistance.
Cite this paper: nullM. MORKS, I. COLE, P. Corrigan and A. KOBAYASHI, "Electrochemical Characterization of Plasma Sprayed Alumina Coatings," Journal of Surface Engineered Materials and Advanced Technology, Vol. 1 No. 3, 2011, pp. 107-111. doi: 10.4236/jsemat.2011.13016.

[1]   M. F. Morks, Yang Gao, N. F. Fahim and F. U. Yingqing, “Microstructure and Hardness Properties of Cermet Coating Sprayed by Low Power Plasma,” Materials Let-ters, Vol. 60, No. 1, 2006, pp. 1049-1053. doi:10.1016/j.matlet.2005.10.073

[2]   M. F. Morks, Yang Gao, N. F. Fahim, F. U. Yingqing and M. A. Shoeib, “Influence of Binder Materials on the Properties of Low Power Plasma Sprayed Cermet Coat-ings,” Surface and Coating Technology, Vol. 199, No. 1, 2005, pp. 66-71. doi:10.1016/j.surfcoat.2005.02.159

[3]   M. F. Morks, A. Ibrahim and M. Shoeib, “Comparative study of Nanostructured and Conventional WC-Co Coat-ings,” Proc. of The International Thermal Spray Confe-rence, Osaka/Japan, ITSC May 2004.

[4]   B. Pavitra, P. Nitin Padture and V. Alexandre, “Improved Interfacial Mechanical Properties of Al2O3 – 13 wt% TiO2 Plasma-Sprayed Coatings Derived from Nanocrystalline Powders,” Acta Materialia, Vol. 51, No. 10, 2003, pp. 2959-2970. doi:10.1016/S1359-6454(03)00109-5

[5]   V. P. Singh, A. Sil and R. Jayaganthan, “A Study on Sliding and Erosive Wear Behaviour of Atmospheric Plasma Sprayed Conventional and Nanostructured Alu-mina Coatings,” Materials and Design, Vol. 32, No. 2, 2011, pp. 584-591. doi:10.1016/j.matdes.2010.08.019

[6]   O. Tingaud, P. Bertrand and G. Bertrand, “Microstructure and Tribological Behavior of Suspension Plasma Sprayed Al2O3 and Al2O3–YSZ Composite Coatings,” Surface & Coating Technology, Vol. 205, No. 4, 2010, pp. 1004- 1008. doi:10.1016/j.surfcoat.2010.06.003

[7]   C.-J. Li, G.-J. Yang and A. Ohmori, “Relationship be-tween Particle Erosion and Lamellar Microstructure for Plasma-Sprayed Alumina Coatings,” Wear, Vol. 260, No. 2, 2006, pp. 1166-1172. doi:10.1016/0272-8842(81)90013-4

[8]   M. Vardelle and J. L. Besson, “Alumina Obtained by Arc Plasma Spraying: A Study of the Optimization of Spraying Conditions,” Ceramics International, Vol. 7, No. 2, 1981, pp. 48-54.

[9]   R. McPherson, “title of the article,” Journal of Material Science, Vol. 8, 1973.

[10]   R. McPherson, “On the Formation of Thermally Sprayed Alumina Coatings,” Journal of Material Science, Vol. 15 , No. 31, 1980, pp. 41-49.

[11]   R. Heung, X. Wang and P. Xiao, “Characterisation of PSZ/Al2O3 Composite Coatings Using Electrochemical Impedance Spectroscopy,” Electrochimica Acta, Vol. 51, No. 8-9, 2006, pp. 1789-1796. doi:10.1016/j.electacta.2005.02.097

[12]   ASTM Standard G 102