Grain Structure and Tensile Properties of As-Cast and Aged Pb–1.1%Sn–0.05%Ca

Abstract

The effects of temperature parameters of casting procedure and aging time at room temperature on the grain structure and tensile properties of Pb–1.1%Sn–0.05%Ca alloy for positive grids of lead-acid batteries were studied by means of optical metallography, scanning electron microscopy, and tensile properties measurements. It was established that with melt or mold temperatures rising, grains in the alloy structure become larger, which causes an increase in the elongation and a decrease in the ultimate tensile strength of the alloy. Natural aging for 32 days does not noticeably change grain size but affects tensile properties of the alloy. Final ultimate tensile strength, yield strength, and Young’s modulus are found to be 2.7, 4.9, and 1.3 times higher, respectively, but the elongation is 2.4 times lower because of the precipitation of intermetallic phases.