Investigation of structural properties of forsterite coating on AZ91 magnesium alloy by sol-gel method
Parvin Siahmard, Reza Amini Najafabadi, Amirhossein Meysami, Mohammad Meysami, Taghi Isfahani
Abstract
This study examined the synthesis and characterization of a nanostructured forsterite coating on a biodegradable AZ91 alloy to enhance its bioactivity. The coating was applied using sol-gel technique, resulting in a homogeneous and crack-free surface as confirmed by scanning electron microscopy. X-ray diffraction was used to identify the phases present in the coating, which confirmed the presence of forsterite particles with an average size of 35 nm. To evaluate the effectiveness of the coating, potentiodynamic polarization electrochemical tests were conducted in simulated body fluid (SBF), which showed that the corrosion current density decreased from 11 μA cm−2 for uncoated samples to 4.3 μA cm−2 for coated samples. Moreover, the surface of the coated magnesium alloy showed fewer cracks and cavities after being immersed in SBF for 672 h. Given that the early degradation of magnesium alloy poses challenges for prostheses and bone stabilizers, this coating could promote bone healing and positive interaction with bone tissue while preventing toxicity from metal ions.