Iranian researchers applied a protecting layer to increase the resistance of stainless steel against corrosion in corrosive environments such as human body.
Results of the research have applications in medical industries, specially in material implants.
Metals are the oldest materials that have been used in medical industries and surgeries. The most important problem with these materials is the negative effects of the released metallic ions caused by corrosion on biological processes in human bodies. The researchers studied corrosive behavior of stainless steel after being coated with a thin film of zirconia to prevent the negative effects of the released metallic ions caused by corrosion on the biological processes in human bodies.
Body simulating liquid and zirconia oxide and zirconia – poly (methyl methacrylate) hybrid coatings were used in this research to study the corrosion. Based on the adhesion results, pure oxide coatings have better adhesion than the hybrid ones. However, malfunction density and porosity are less in hybrid coatings than in oxide ones, based on the corrosion tests.
In addition to the test results, other experiments show that homogeneous and local resistance to corrosion increase as the number of the layers increases and the film becomes thicker. In other words, the anticorrosion mechanism is to create a physical block in front of the electrolyte. Therefore, as the thickness increases, the diffusivity into the physical block decreases and the availability of the substrate would be more difficult.
Results of the research have been published in Ceramics International, vol. 40, issue 2, March 2014, pp. 2857-2861.