Microstructure modulation realizing high performance of Pb-Ag alloys by controlled solidification temperature

Abstract

The microstructure of the Pb-Ag alloy is vital to its mechanical, corrosion and electrochemical properties. In this paper, heat preservation mold is used to control the temperature of cast lead alloy, realizing the regulation of the microstructure of Pb-Ag alloy. The effects of the surface microstructure and the Ag distribution on the mechanical, corrosion-resistant and electrochemical properties of lead alloy are investigated. The results show that the heat preservation treatment effectively enhances the longitudinal tissue uniformity of the alloy, and optimizes the distribution of Ag in the alloy. The alloy shows the best comprehensive performance as the heat preservation temperature reaches 50 ℃ due to the uniform size of the metallographic structure and the most uniformly distributed Ag. The low-temperature heat preservation treatment (12 ℃) refines the middle and bottom grains of the alloy and enhances the mechanical properties of the alloy. However, the increased uniform grain size and Ag distribution at the longitudinal level of the alloy led to a decrease in the electrochemical properties and corrosion resistance.