Cu ions release and the formation of CuO/Cu2O during PEO based on the work function

Abstract

The Cu ions release was investigated by the work function by scanning kelvin probe (SKP), and the formation of CuO/Cu2O was also researched by recording plasma discharges during plasma electrolytic oxidation (PEO) of Ti-14Cu alloy with different morphologies Ti2Cu phase. It is found that L-Ti2Cu phases with lower work function enhances the escape of Cu valence electrons from the 4 s energy level more easily compared to the G-Ti2Cu and GL-Ti2Cu phases. Consequently, this leads to earlier Cu ions released from L-Ti2Cu phases as opposed to the G-Ti2Cu and GL-Ti2Cu phases. The earlier Cu+ released from L-Ti2Cu phases increases the formation of Cu2O and further oxidizes into CuO with increasing voltage, which lead to the enhanced the relative content of CuO. This enhancement contributes to improving antibacterial activity and tribocorrosion resistance due to stress response and lubrication effect by high relative content of CuO. This research provides a theoretical reference for the metal ions release of Ti-14Cu alloy in oxidation dissolution process of PEO and the formation of corresponding metal oxides.