Imparting increased corrosion passive and bio-active character to Al2O3 based ceramic coating on AZ91 alloy

Magnesium alloys have their properties similar to natural human bone. However, their uncontrolled degradation and low wear resistance in physiological environment are major obstacles for their use as bioimplant. Ceramics coatings are known as passive coatings to combat corrosion under corrosive environment. Present work is an attempt to impart bio-active character to ceramic based coatings, for that CeO2 is used as dopant to Al2O3 coatings. D-gun spray technique was used to deposit coatings on solution treated AZ91 alloy. The deposited coatings were evaluated for corrosion response (potentiodynamic polarization) and biocompatibility (protein adsorption, cytotoxicity, cell viability, and proliferation by live/dead cell assay and MTT assay (colorimetric assay used for reduction of yellow tetrazolium salt (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)). The exposed alloys (bare and coated) were characterized using fluorescence microscope and (SEM) scanning electron microscope, XRD (X-ray diffraction). It was observed that doping of CeO2 played important role in controlling the cell proliferation in a unique manner and imparted corrosion passive and bio-active characters.