Controlled degradation of a magnesium alloy in simulated body fluid using hydrofluoric acid treatment followed by polyacrylonitrile coating

In vitro study of polycaprolactone/bioactive glass composite coatings on corrosion and bioactivity of pure Mg

“…Still, the poor corrosion resistance of magnesium does not meet the demands for numerous applications. Hence, surface modification and application of coatings are receiving increased attention [25,26,32,35,38,40]. As summarized in a previous review on degradable coatings on magnesium by Hornberger et al [25], microarc oxidation (MAO), ion implantation, anodisation, electro-deposition, phosphating treatment, physical vapor deposition, electrophoretic deposition and polymer coatings have been in focus of research in recent times.…”

“…Magnesium and magnesium alloys could therefore be effective as bioabsorbable implants (or tissue scaffolds) for short term implantation, with beneficial properties such as inducing the formation of new bone [2,7,15,18,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. In this context, these materials readily corrode in the physiological environment and pathological tissue should heal at the same time, e.g.…”

Fluoride conversion coatings for magnesium and its alloys for the biological environment

“…Such adhesion improvement allows self-healing processes to take place at the interface of an HF-treated/polymer-coated sample, as confirmed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analysis (Conceição et al, 2010(Conceição et al, , 2011b(Conceição et al, , 2012. These self-healing processes produce impedance increases after a certain exposure time to the corrosive solution.…”

“…It was shown that the impedance of AZ31 sheets coated with MgF 2 (2.0 mm of thickness) falls by 4 decades after 20 h of exposure to a 3.5 wt% NaCl solution (Conceição et al, 2010). For instance, Conceição et al (2010), Conceição et al (2011a,b), and Conceição, Scharnagl, Dietzel, and Kainer (2012) have shown that polymer coatings on HF-treated magnesium substrates behave much better than on the substrates with other kinds of pretreatments. This indicates that the corrosive solution can easily penetrate in the coating, reaching the metallic substrate in short time periods.…”

“…In the study of Conceição et al (2012) it was shown that the performance of AZ31 sheets pretreated with HF and postcoated with PAN was inferior in SBF in comparison to a 3.5 wt% NaCl solution. In the study of Conceição et al (2012) it was shown that the performance of AZ31 sheets pretreated with HF and postcoated with PAN was inferior in SBF in comparison to a 3.5 wt% NaCl solution.…”