Homogeneous Microstructure Improving the Mechanical and Electrochemical Properties of Lead Alloys by Stirring Treatment

Abstract

Homogeneous microstructure in lead alloy matrix plays an important role in improving its mechanical and electrochemical properties. In this work, different stirring speed provided during the melt casting of the alloy are tended to obtain lead alloys with different microstructure. The results show that proper stirring speed is beneficial for improving the overall homogeneity of the alloy, however, as the stirring speed is too high, plenty of second phase impurities and defects produced in the lead matrix, which possesses negative effect on the mechanical and electrochemical properties. The most uniform composition and homogeneous microstructure was obtained when the stirring speed is 100 r/min, which is conducive to the decrease of oxygen evolution potential of 30 mV and charge transfer resistance of 22.77%, and the increase of the corrosion resistance of 1.49%, and promote the generation of the uniform and dense PbO2 protective layer.