Patent ID: 6342110
Filing Date: 2002-01-29
Classification: C22C,C22F,H01M,Y02E

Abstract:
Recrystallized lead or lead alloy positive lead-acid battery electrodes which have been processed to improve at least one of the properties of (i) creep, (ii) intergranular cracking and (iii) intergranular corrosion resistance, by subjecting said lead or lead alloy to at least one cycle consisting of the sequential steps of:a. cold working the lead or lead alloy by an amount of approximately 10-80%; and b. annealing the lead or lead alloy at a temperature in the range of 150-280Â° C. for a period in the range of from 10 seconds to 20 minutes, sufficient to effect recrystallization of the lead or lead alloy and a substantial increase in the concentration of special grain boundaries thereof wherein the percentage of special grain boundaries comprises at least 50% of the total grain boundaries thereof and said lead or lead alloy has a hardness after said increase in the concentration of said special grain boundaries which is not greater than the hardness of said lead or lead alloy before said increase in the concentration of said special grain boundaries; and said lead alloy consists essentially of lead alloyed with Ag, Sn, Cu, Zn, As, Bi, Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba or Ra.