Microstructures and corrosion resistance of PbCaSnAl-M (M=Mg, Sr, Ba) grid alloys

The corrosion of positive grid alloys is important for determining the service life of lead-acid batteries (LABs). Herein, we prepared a series of PbCaSnAl-M (M = Mg, Sr, Ba) alloys by an induction melter and systematically investigated the effect of Mg, Sr and Ba on their microstructures and corrosion resistance. The results show that the average grain size of PbCaSnAl-Mg reduces from 14.56 um to 11.96 um, and the average grain size of PbCaSnAl-Sr and PbCaSnAl-Ba increases to 25.95 um and 39.17 um, respectively. The addition of Sr and Ba reduces the corrosion rate of PbCaSnAl alloys from 0.366 mg h-1 cm- 2 to 0.258 and 0.289 mg h-1 cm-2, respectively. The increase corrosion resistance is due to the Sr and Ba change the microstructures of the corrosion layer and improve the densification of the corrosion layer.