A New Lead Alloy Current-collector Manufactured By A Powder Rolling Process And Its Corrosion Behavior Under Lead-acid Battery Conditions

摘要

A new powder rolling process for manufacturing current-collector sheets for lead-acid batteries has been developed. Gas-atomized lead-tin and lead-tin-calcium alloy powders obtained by a rapid solidification process in air were employed as raw materials for the powder rolling process. The corrosion behavior of powder-rolled lead-tin alloys with various compositions of tin has been investigated. A dipping corrosion test of square plain sheets of the alloys was performed in H_2SO_4 at 75℃. The test was repeated up to 20 cycles with each cycle consisting of a controlled 10 mA cm~(-2) oxidation current for 6h and a rest under open circuit voltage for 6h. The extent of corrosion-elongation and the appearance of the corroded surface of the tested specimens were the main observations. The corrosion-elongation of the corroded sheet of a powder-rolled lead alloy containing 1.5 wt% tin with ca. 200μm initial thickness was less than 5%, whereas that of the corroded sheet of the cast-rolled lead alloy containing 1.5 wt% tin with the same initial thickness was 25-30% under the same corrosion test conditions. The corroded powder-rolled sheet of the 1.5 wt% tin lead alloy has uniform corrosion, but the cast-rolled sheet of lead alloy containing 1.5 wt% tin was much distorted and was perforated by the corrosion. Intergranular corrosion of the powder-rolled lead-tin alloys was much suppressed as compared with that of the cast-rolled lead-tin alloys.