Microstructures and Corrosion Resistance of Magnesium Implanted with Nitrogen Ions

The influence of the nitrogen ion implantation on the corrosion resistance of magnesium has been studied. The nitrogen solid solution and Mg3N2 were detected by the grazing incidence X-ray diffraction analysis. TEM observations revealed the morphology of Mg3N2 and cavities in magnesium matrix. Anodic polarization measurements showed that implantation with 1×1021 N2+⁄m2 at 150 keV greatly reduce the current density at all applied voltage. The higher accelerating voltage showed better corrosion resistance. The amount of Mg3N2 was increased with increasing dose resulting in the degradation of corrosion resistance. The corrosion resistance of implanted specimen was also degraded by annealing.