Silver additions to lead-calcium-tin alloys

Silver additions to lead-calcium-tin alloys. Silver has been added to lead-calcium-tin alloys to increase the resistance to creep and corrosion, and to prevent growth of the positive grids at elevated temperatures. Valve-regulated lead-acid batteries often operate at elevated temperatures and/or produce high internal 

Silver has a significant effect in delaying the discontinuous precipitation reaction as well as the overageing of calcium precipitates [90]. Silver also increases the corrosion resistance of lead-calcium tin alloys — particularly under conditions that simulate end-of-discharge (high pH) conditions — and improves the cycle-life and capacity of VRLA batteries. Silver decreases the thickness of the PbO layer but produces a harder, more compact, corrosion layer than tin. Silver does not, however, increase the conductivity of the corrosion layer. 

Silver imparts little improvement to the mechanical properties of lead-calcium tin-(silver) alloys which are fully aged (Table 2.6), but gives lower elongation in both cast and rolled alloys. There is no effect on the microstructure at 0.03 wt.% Ag [51]. Significant improvement in creep resistance has been observed in alloys which contain silver [99]. Significant increases in cycle-life and capacity have been described 

Silver is reported to segregate to the grain and sub-grain boundaries of lead-calcium-tin alloys [94]. Microprobe analysis of the cross-section of grid wires produced from cast and rolled lead-calcium-tin alloys with a bulk silver content of 

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