Study of Process Affected by Electrolyte Concentration through Microarc Oxidation on the TC4 Alloy Surface

Fengbiao Wang^*, Yongqing Wang, Bo Hou, Jiakun Wu, Yapeng Li

School of Mechanical Engineering, Dalian University of Technology, Dalian, China.

DOI: 10.4236/oalib.1101199                

Abstract

This paper aims to achieve the prepared functional coatings containing a specific ratio of calcium and phosphorus, and guide the rational allocation of chemical reagents. On the medicinal titanium alloy surface the calcium biocoating and phosphorus biocoating were fabricated by micro arc oxidation (MAO) process. The coating morphology and elemental composition were observed by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). Wear resistant test on the coating surface was executed. The effect regulars of different concentrations and different molar ratio of electrolyte on the calcium and phosphorus content of medical TC4 alloy coating on micro arc oxidation system were researched, and the effects of electrolyte concentration on the molar ratio of calcium and phosphorus in the coating were also studied. The experimental results show that, with the increase of the electrolyte concentration, calcium content and phosphorus content in the coating are all decreased. But the ratio of calcium and phosphorus in the coating is increased, and the concentration of Ca/P molar ratio is higher, while calcium content and phosphorus content in coating are all lower. Wear resistant test shows that proper electrolyte concentration is helpful to improve the surface properties of coating. So if it wants to prepare one certain Ca/P molar ratio biocoating, the ratio can determine the different electrolyte concentrations of Ca/P molar ratio, and at last determine roughly the ratio of the compound reagent.

Keywords

Calcium and Phosphorus Ratio, Micro-Arc Oxidation, Electrolyte Concentration, Wear Resistant

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Mcpherson, R., Gane, N. and Bastow, T. (1995) Structural Characterization of Plasma Sprayed Hydroxyapatite Coatings. Journal of Materials Science-Materials in Medicine, 6, 327-334. http://dx.doi.org/10.1007/BF00120300
[2]	Qiao, J.Q. and Wang, F.B. (2012) Fracture Mechanics of Composite Ceramic Coating Prepared by Micro-Arc Oxidation on Biomedical Titanium Alloy. Plating and Finishing, 34, 18-23.
[3]	Mendes, S.C., Reis, R.L., Bovell, Y.P., et al. (2001) Biocompatibility Testing of Novel Starch-Based Materials with Potential Application in Orthopaedic Surgery: A Preliminary Study. Biomaterials, 22, 2057-2064. http://dx.doi.org/10.1016/S0142-9612(00)00395-1
[4]	Guan, Y.J., Xia, Y. and Li, G. (2008) Growth Mechanism and Corrosion Behavior of Ceramic Coatings on Aluminum Produced by Auto Control AC Pulse PEO. Surface and Coatings Technology, 202, 4602-4612.
[5]	Ishizawa, H. and Ogino, M. (1995) Formation and Characterization of Anodic Titanium Oxide Films Containing Ca and P. Journal of Biomedical Materials Research, 29, 65-72. http://dx.doi.org/10.1002/jbm.820290110
[6]	Yerokhin, A.L., Nie, X., Leyland, A., Matthews, A. and Dowey, S.J. (1999) Plasma Electrolysis for Surface Engineering. Surface & Coatings Technology, 122, 73-93. http://dx.doi.org/10.1016/S0257-8972(99)00441-7
[7]	Sul, Y.T. (2003) The Significance of the Surface Properties of Oxidized Titanium to the Bone Response: Special Emphasis on Potential Biochemical Bonding of Oxidized Titanium Implant. Biomaterials, 24, 3893-3907. http://dx.doi.org/10.1016/S0142-9612(03)00261-8
[8]	Harimkar Sandip, P. and Dahotre Narendra, B. (2008) Microindentation Fracture Behavior of Laser Surface Modified Alumina Ceramic. Scripta Materialia, 58, 545-553.
[9]	Khorasanian, M., Dehghan, A., Shariat, M.H., et al. (2011) Microstructure and Wear Resistance of Oxide Coatings on Ti-6Al-4V Produced by Plasma Electrolytic Oxidation in an Inexpensive Electrolyte. Surface and Coatings Technology, 206, 1495-1502.
[10]	Son, W.W., Zhu, X., Shin, H.I., Ong, J.L., et al. (2003) In Vivo Histological Response to Anodized and Anodized/ Hydrothermally Treated Titanium Implants. Journal of Biomedical Materials Research Part B: Applied Biomaterials, 66B, 520-525. http://dx.doi.org/10.1002/jbm.b.10042
[11]	Li, L.H., Kong, Y.M., et al. (2004) Improved Biological Performance of Ti Implants Due to Surface Modification by Microarc oxidation. Biomaterials, 25, 2867-2875. http://dx.doi.org/10.1016/j.biomaterials.2003.09.048
[12]	Wang, F.B., Di, S.C. and Yu, J. (2011) Biocompatibility Research of Medicine Titanium Alloy Coating by Microarc Oxidation. Advanced Materials Research, 189, 222-226.
[13]	Harimkar, S. and Dahotre, N.B. (2007) Laser Assisted Densification of Surface Porosity in Structural Alumina Ceramic. Physica Status Solidi (A), 204, 1105-1113.
[14]	Harimkara Sandip, P. and Dahotre Narendra, B. (2008) Characterization of Microstructure in Laser Surface Modified Alumina Ceramic. Materials Characterization, 59, 700-707.
[15]	Mateos, J., Cuetos, J.M., Fernandez, E., et al. (2001) Tribological Properties of Plasma Sprayed and Laser Remelted 75/25 Cr3C2/NiCr Coatings. Tribology International, 34, 345-351.
[16]	Yerokhin, A.L., Snizhko, L.O., Gurevina, N.L., et al. (2004) Spatial Characteristics of Discharge Phenomena in Plasma Electrolytic Oxidation of Aluminium Alloy. Surface and Coatings Technology, 177-178, 779-784. http://dx.doi.org/10.1016/j.surfcoat.2003.06.020