Enhancement of corrosion resistance and mechanical properties of Mg–1.2Ca–2Bi via a hybrid silicon-biopolymer coating system

• Main Authors: Bakhsheshi-Rad, H. R., Hamzah, E., Daroonparvar, M., Abdul Kadir, M. R., Kasiri-Asgarani, M., Staiger, M. P.
• Format: Article
• Published: Elsevier B.V. 2016
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://eprints.utm.my/id/eprint/72168/; https://www.scopus.com/inward/record.uri?eid=2-s2.0-84983543601&doi=10.1016%2fj.surfcoat.2015.09.039&partnerID=40&md5=a1288bfb8ae04b3ccdd85e9752a705da

In this work, a hybrid dual layer surface coating consisting of a silicon (Si) underlayer and poly(ε-caprolactone) (PCL) overlayer was investigated that was designed to reduce the corrosion rates of magnesium-based biomaterials. The Si underlayer was 1.2 μm thick and composed of spherical nanoparticles. The overlayer of PCL was 75.2 μm thick and comprised network of pores. Corrosion-induced reduction of the compressive strength of a Si/PCL-coated Mg–Ca–Bi alloy was lower than that of the uncoated or Si layer-coated alloys. However, the bonding strength of the Si coating (24.6 MPa) was significantly higher than that of the Si/PCL-coated samples (6.8 MPa). The Si/PCL coating dramatically enhances the charge transfer resistance of the Mg alloy (2.11 kΩ cm2) in simulated body fluid when compared with a Si-coated sample (2265.12 kΩ cm2). Si/PCL coatings are considered a promising route to control the corrosion rate and mechanical properties of Mg-based biomaterials.