Evolution of Mechanical Properties of Pb–Sb–Sn–As–Se Grid Alloys for Lead-Acid Batteries During Natural Aging

This study is devoted to the investigation of mechanical properties of a series of low-antimony Pb–Sb–Sn–As–Se grid alloys for lead-acid batteries in as-cast condition and after natural aging during storage. Mechanical properties were characterized by ultimate tensile strength, yield strength, elongation, and Young's modulus determined at room temperature using TIRAtest 2300 and P-0.5 universal testing machines. For most investigated as-cast alloys, an increase in ultimate tensile strength is accompanied by an increase in elongation. Within the temperature range between 70 ºС and 150 ºС, higher heating temperature of a casing mold does not markedly affect average elongation but causes the slight decrease (by ~4 %) in average ultimate tensile strength. When aged during storage for 30–33 days, the Pb–Sb–Sn–As–Se grid alloys, attain higher values of ultimate tensile strength, yield strength, and Young's modulus but lower values of elongation. This is due to precipitation of second-phase particles from lead-based solid solution oversaturated by antimony, arsenic, and selenium. The most noticeable effect of strengthening is observed during first five days of natural aging.