Evaluation of biodegradability and electrochemical behavior of magnesium-aluminum alloy AZ91 with bio-nanocomposite membrane

One of the most important problems of using magnesium alloys is their high corrosion rate. In order to solve this problem, the method of surface modification and coating has been considered. The main purpose of this research is to apply polycaprolactone/chitosan-1% Baghdadite polymer membrane by immersion method on anodized magnesium-aluminum AZ91 alloy in order to improve the corrosion resistance, biodegradability and biocompatibility of this alloy. The results of the electrochemical test show the improvement of the electrochemical resistance and the reduction of the electrochemical current density (10^3 times reduction) of the anodized magnesium-aluminum alloy AZ91 due to the application of the polymer-ceramic membrane. Also, the application of polymer-ceramic membrane has led to an increase in the surface roughness from 0.329 ± 0.02 (magnesium-aluminum AZ91) to 7.792 ± 0.34 micrometers. In order to evaluate the ability of apatite formation on the samples, the body simulating liquid test (phosphate buffer) was used. The results show that the formation of apatite layer on the surface of the sample can be considered as a measure of biodegradability