Effect of Ti Corrostion on Separation of Electro-Deposited Cu Foil

Cu foils by electroplating are known for many industrial applications such as PCB and Li ion batteries. Ti metal is commonly used as the cathode for the Cu reduction from sulfate solution. Under an acidic and high temperature environment, the passivation layer on the surface of the titanium metal tends to react with acidic solution. As a result, the corrosion of the active titanium metal was observed. In this study, the corrosion behavior of commercial pure titanium in acid copper sulfate baths was investigated, and several surface treatments were used to improve the corrosion resistance of titanium passive layer. The microstructure of titanium metal after immersion in acid copper sulfate solution was examined by using SEM and FIB. The pitting corrosion of Ti was clearly observed using SEM. The corrosion mechanism of the titanium metal in the sulfuric acid solution was discussed. In addition, the electrochemical characteristics of commercial pure titanium metal in sulfuric acid solution were also analyzed using the three-pole potential measurement method.