Effect of Cu content on antibacterial activity of 17-4 PH stainless steel

The 17-4 PH stainless steels with four different copper (Cu) contents were fabricated, and their antibacterial performances were studied by means of antibacterial test, TEM observation, Vickers hardness measurement and electrochemical test. The results showed that the Cu seriously influenced the antibacterial performance of 17-4 PH stainless steel. The higher the Cu content in the steel, the better the antibacterial activity and the higher the micro-hardness of the 17-4 PH stainless steel. The Cu content in the 17-4 PH stainless steel should be above 4.5 wt-% to exhibit better antibacterial activity. The electrochemical test showed that the Cu content would also affect the Cu ions release behaviour of the 17-4 PH stainless steel, which eventually influence the antibacterial activity.