Deposition of microarc oxidation–polycaprolactone duplex coating to improve the corrosion resistance of magnesium for biodegradable implants

• Published in: Thin solid films 2014-07, Vol.562, p.561-567
• Main Authors: Li, Long-Hao, Sankara Narayanan, T.S.N., Kim, Yu Kyoung, Kong, Young-Min, Park, Il Song, Bae, Tae Sung, Lee, Min Ho
• Format: Article
• Language: English
• Subjects: Biodegradability; Biodegradation; Coating; Corrosion resistance; Cross-disciplinary physics: materials science; rheology; Deposition; Exact sciences and technology; Immersion test; Implants; Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids); Magnesium; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Micro-arc oxidation; Physics; Polycaprolactone; Potentiodynamic polarization; Protective coatings
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2014.04.004

The present study addresses the deposition of a duplex coating by microarc oxidation (MAO) treatment and polycaprolactone (PCL) coating to improve the corrosion resistance of Mg. A uniform PCL coating layer is formed by dip coating method on MAO treated Mg, and the corrosion resistance of MAO–PCL duplex coated Mg is evaluated by potentiodynamic polarization study and immersion test. The results reveal that the porous nature of MAO treated Mg fails to offer a better corrosion resistance in Hanks' balanced salt solution (HBSS). However, deposition of PCL coating (using 4 and 7wt.% PCL) over MAO treated Mg significantly increased the corrosion resistance of Mg in HBSS for 7days. The MAO–PCL duplex coating can be a good alternative method of protecting Mg from rapid corrosion for biodegradable implant applications. •Polycaprolactone (PCL) is uniformly coated on microarc oxidation (MAO) treated Mg.•The PCL coating helps to seal the pores of the MAO treated Mg.•MAO–PCL duplex coating significantly improved the corrosion resistance of Mg.