Studies on the Anodic Dissolution of Copper at High Current Densities

摘要

A fundamental investigation was conducted on the influence of electrochemical and mass transfer phenomena on the anodic dissolution of copper under conditions comparable to electrochemical machining. Maximum current densities of 80 amp/cm2 and flow rates of 600-700 cm/sec were used in a 3 mm wide rectangular flow channel with a 1 mm electrode separation. The apparent valence of copper dissolution was determined from anode weightloss measurements at various flow rates in 2N KNO3, 1N K2SO4, 1N H2SO4, and 2N KCl. an experimental determination, using a commercial oxygen analyzer, showed that less than 1% of the total current was consumed in the anodic evolution of oxygen. A motion picture study of anodic copper dissolution under free convection verified that the formation of passivating layers is associated with a step increase in cell voltage. (Author)