Study on the microstructure and electrochemical properties of lead–calcium–tin–aluminum alloys

A detailed investigation of the effects on the microstructure and electrochemical properties of lead–calcium–tin–aluminum alloys of adding tin and calcium was undertaken. Cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) were used to study the anode electrochemical behavior (such as the growth of lead dioxide, a passive film and the evolution of oxygen) of the lead grid alloy in sulfuric acid solution. The structure and corrosion morphology of the lead alloy were observed and analyzed using a polarizing microscope, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The experimental results show that the grains gradually became smaller as the content of calcium increased, and the content of tin decreased, in the alloy. The size and shape of grains were related to the ratio of tin to calcium content in the alloys. The linear sweep voltammetry and AC impedance measurements suggested that the preferred ratio of tin to calcium content, r, is between 9 and 15, and the optimum range of tin content in the alloys is 0.8–1.1%.