The Effect of Heat-Treatment, Hot-Rolling and Anodizing on Corrosion Behavior of Biocompatible Magnesium Alloy Containing Zinc, Calcium and Rare Earth Elements

In this paper, the effects of anodizing, solution heat-treatment and hot-rolling on microstructure and corrosion behavior of a biocompatible magnesium alloy containing Zn, Ca, and rare earth elements (REEs) were investigated. The anodizing process using HAE method in 3 various current densities and 2 different times was performed on each of the specimens. The corrosion resistance of samples was evaluated by immersion test in PBS solution at 37 ° C. The resulting oxide film were studied by scanning electron microscopy and the weight loss of the specimens was measured after eliminating the oxide residues. The results showed that a uniform structure with increased grain size is made by solution heat-treatment. This treatment had a favorable effect on the corrosion resistance of the alloy and reduced the corrosion rate by 20%. The hotrolling process likewise increased grain size and reduced the corrosion rate by 9%. Also, the anodizing process generally had a favorable effect on the corrosion properties of the specimens and in the best condition, caused 80% reduction in the corrosion rate. The effect of time and applied current density of the anodizing process was also studied. Results showed different effects for each of samples.