Preparation of lead alloy anodes and their anodic properties

Some lead alloy anodes prepared by open air casting or by vacuum diffusion bonding and their electrolytic properties are studied using Pb-5%Sn, Pb-0. 5%Ag, and Pb-l%In-0. 5%Ag alloys, respectively. The Pb-5%Sn anode prepared by vacuum diffusion bonding method at 750°C shows lower oxygen over-voltage (1.75V vs. SCE) than that of another anodes. After anodic oxi- dation, compact oxide layer with single a-Pb02 is observed on this surface, the other anodes have oxide layer with combined ot-Pb0₂ and (3-Pb0₂or PbS0 ₄. The rate of weight-loss of this anode is less than that of the other Pb-5%Sn anodes prepared by open air casting method, the rate of weight-loss of Pb-0. 5%Ag and Pb-l%In-0. 5%Ag anodes are less than Pb-5%Sn anodes. It is found that the Pb-5%Sn anode prepared by high temperature vacuum diffusion bonding method is preferable to use for high speed electrogalvanizing, because of low oxygen over voltage, low weight loss, and low lead pollution, comparatively.