The Effects of Nano-SiO₂ on the Chemical Composition of Layers on Aluminum Alloy by Micro-Arc Oxidation

Abstract:

In this article, a nano-SiO₂/micro-arc oxide composite coating layer was prepared on the surface of 7A52 Aluminum alloy by addition of SiO₂ nanoparticles into the micro-arc oxidation electrolyte to enhance the performance of the formed oxidative layer. Then, the composite oxidative layer was characterized by X-ray Photoelectron Spectroscopy (XPS) to investigate its elemental and chemical compositions, as well as their respective distributions. The results revealed that at elevated temperatures resulted from micro-arc discharge, the SiO₂ in the composite reacted with Al₂O₃ (the major content of the micro-arc oxidative layer) to form a new compound known as mullite. In addition, the contents of SiO₂ and γ-Al₂O₃ in the inner layer of the oxidative layer were lower than those in the surface layer. This can be explained by the higher temperature in the inner layer which motivated the formation of mullite and α-Al₂O₃ from SiO₂ and γ-Al₂O₃ respectively during the micro-arc oxidation process.

• Periodical: Applied Mechanics and Materials (Volume 628)
• Pages: 84-88
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.628.84
• Online since: September 2014
• Authors: Xiang Bo Suo*, Ji Qiu, Shi Ning Ma, Hong Mei Wang
• Keywords: Aluminium Alloy, Chemical Composition, Micro-Arc Oxidation, Nanocomposite, X-Ray Photoelectron Spectroscopy

References

[1] A.L. Yerokhin, X. Nie, A. Leyland, A. Matthews, S. J. Dowey. Plasma Electrolysis for Surface Engineering. Surf. Coat. Technol., 122 (1999) 73-93.

DOI: 10.1016/s0257-8972(99)00441-7

[2] L. R. Krishna,K. R. C. Somaraju,G. Sundararajan. The Tribological Performance of Ultra-hard Ceramic Composite Coatings Obtained through Microarc Oxidation. Surf. Coat. Technol., 163-164 (2003) 484-490.

DOI: 10.1016/s0257-8972(02)00646-1

[3] J. A. Curran,T. W. Clyne. The Thermal Conductivity of Plasma Electrolytic Oxide Coatings on Aluminium and Magnesium. Surf. Coat. Technol., 199 (2005) 177-183.

DOI: 10.1016/j.surfcoat.2004.11.045

[4] E. Matykina,A. Berkani,P. Skeldon G.E. Thompson. Real-time Imaging of Coating Growth during Plasma Electrolytic Oxidation of Titanium . Electrochimica Acta. 53 (2007) 1987-(1994).

DOI: 10.1016/j.electacta.2007.08.074

[5] A. L. Yerokhin,A. Shatrov,V. Samsonov,P. Shashkov,A. Pilkington,A. Leyland,A. Matthews. Oxide Ceramic Coatings on Aluminium Alloys Produced by a Pulsed Bipolar Plasma Electrolytic Oxidation Process. Surf. Coat. Technol., 199 (2005) 150-157.

DOI: 10.1016/j.surfcoat.2004.10.147

[6] P. I. Butyagin,Y. V. Khokhryakov,A. I. Mamaev. Microplasma systems for creating coatings on aluminium alloys. Materials Letters, 57 (2003) 1748-1751.

DOI: 10.1016/s0167-577x(02)01062-5

[7] J. Fanya,T. Honghui,L. Jiong,S. Liru. Structure and Microwave-absorbing Properties of Fe-particle Containing Alumina Prepared by Micro-arc Discharge Oxidation. Surf. Coat. Technol., 201 (2006) 292-295.

DOI: 10.1016/j.surfcoat.2005.11.116

[8] W. Zhang,K. Du,C. Yan,F. Wang. Preparation and characterization of a novel Si-incorporated ceramic film on pure titanium by plasma electrolytic oxidation. Applied Surface Science, 254 (2008) 5216-5223.

DOI: 10.1016/j.apsusc.2008.02.047

[9] E. Matykina,R. Arrabal,F. Monfort,P. Skeldon G.E. Thompson. Incorporation of Zirconia into Coatings Formed by DC Plasma Electrolytic Oxidation of Aluminium in Nanoparticle Suspensions. Applied Surface Science, 255 (2008) 2830-2839.

DOI: 10.1016/j.apsusc.2008.08.036

[10] Suo Xiang-bo, Ma Shi-ning, Qiu Ji, Lv Qing-xing. Improvement of Surface porosity and properties of MAO ceramic coatings by incorporation of SiO2 nanoparticles. Journal of Aeronautical Materials, 29 (2009) 66-69. (In Chinese).

[11] Shining Ma, Xiangbo Suo, Ji Qiu. Fabrication of n-SiO2 reinforced Al2O3 composites coatings on 7A52 aluminum alloy by micro-arc oxidation. Advanced Materials Research, 97~101 (2010) 1463~1466. (In Chinese).

DOI: 10.4028/www.scientific.net/amr.97-101.1463

[12] Suo Xiang-bo, Qiu Ji, Zhu Hai-yan. Effects of n-SiO2 on growth dynamics of alumina coatings Formed on 7A52 aluminum alloy by micro-arc oxidation; MA Shi-ning, Journal of Aeronautical Materials, 32 (2012) 27-30. (In Chinese).

[13] J. F. Moulder, W. F. Stickle, P. E. Sobol. Handbook of X-ray Photoelectron Spectroscopy. Physical Electronics, Inc. USA.

[14] J A Curran, T W Clyne. The thermal conductivity of Plasma electrolytic Oxide coatings on aluminium and magnesium. Surf. Co-at. Technol., 199 (2005) 177~183.

DOI: 10.1016/j.surfcoat.2004.11.045

[15] Suo Xiang-bo. Fabrication, characterization and properties of nanocomposite coating on aluminum alloy prepared by micro-arc oxidation. the Academy of Armored Forces Engineering, Beijing, 2010. (In Chinese).

[16] W. Xue,Z. Deng,Y. Lai,R. Chen. Analysis of Phase Distribution for Ceramic Coatings Formed by Microarc Oxidation on Aluminum Alloy.J. Am. Ceram. Soc., 81 (1998) 1365-1368.

DOI: 10.1111/j.1151-2916.1998.tb02493.x