Antibacterial property of Ce-bearing stainless steels

Rare earth (RE) elements inhering in low toxicity have been widely used in biomedicine. The RE elements can also improve the hot workability, corrosion resistance and mechanical properties of stainless steels. However, the antibacterial mechanisms of the RE elements are still under discussion and the antibacterial property of RE-bearing stainless steels has not yet been investigated or reported so far. In this paper several Ce-bearing stainless steels were prepared, the microstructure of the steels was examined, and the antibacterial property of Ce-bearing stainless steels was investigated. It was found that Ce-rich zones were precipitated in the Ce-bearing stainless steels and the volume fraction of the Ce-rich zones increased with increasing Ce content. The Ce-bearing stainless steels showed excellent antibacterial property when the amount of Ce added was above a critical value. Compared to the conventional Cu-bearing antibacterial stainless steels, the Ce-bearing stainless steels investigated presently exhibited good antibacterial ability without any thermal aging treatment. The antibacterial mechanism of Ce-bearing stainless steels is also discussed.