HARDENING PROCESS IN TERNARY LEAD-ANTIMONY-TIN ALLOYS FOR BATTERY GRIDS

It is known that lead-antimony alloys are very well hardened by contin uous precipitation, whereas lead-tin alloys present a discontinuous pr ecipitation with a weak hardening effect. In these binary alloys, ther e is precipitation of either antimony or tin. In ternary alloys, the c ompound SbSn can also precipitate. This study is focused on the type o f precipitation, the nature and the morphology of the precipitated pha ses, and the intensity of hardening in ternary Pb-Sb-Sn alloys in rela tion to the composition of the alloys and the ternary diagram. To simu late the different processes of grid production, four states are studi ed, namely, as-cast product, rehomogenized, cold worked, cold worked a nd rehomogenized. The alloys contain up to 2.5 wt.% Sb and 2.5 wt.% Sn .