Effect of Trace Rare Earth Ce on Microstructure and Corrosion Resistance of Pure Aluminum

In moderately and severely corroded atmosphere, the outer aluminum conductor material of steel-cored aluminum strand suffered persistent corrosion due to the action of corrosive medium. In this paper, a variety of physical and chemical inspection methods, such as macroscopic observation, chemical composition analysis, scanning electron microscopy (SEM), energy spectrum (EDS) analysis and neutral salt spray corrosion test, were used to treat the aluminum conductor material after rare earth modification. The refining effect of Ce on the microstructure of pure aluminum was analyzed. The initial corrosion time of samples with different Ce content and the average corrosion rate of samples after 240 h neutral salt spray corrosion test were obtained. The reasons for the improvement of corrosion resistance of pure aluminum materials by Ce were preliminarily discussed. The results showed that Ce could refine the grain size of pure aluminum. In the selected samples Al-xCe (x=0, 0.024, 0.045, 0.070, 0.110, 0.140), the average grain size of the samples decreased gradually with the increase of Ce content. After adding Ce in pure aluminum, some Ce bound with impurities to promote the impurities in the as-cast structure. The corrosion resistance of pure aluminum could be effectively improved by adding appropriate amount of Ce. Among the selected samples, Al-0.070Ce had the best corrosion resistance, the initial corrosion resistance time was 168 h, which was 40% higher than that of pure aluminum, and the average corrosion rate was 1.6307 mg•dm-2•d-1, only 47.06% of pure aluminum samples. © Editorial Office of Chinese Journal of Rare Metals. All right reserved.