Effect of adding different contents of mercury to magnesium on discharge and corrosion performances of magnesium anode sheet

Abstract

Discharge and corrosion performances of magnesium alloy anode sheets with content of Hg 1∼3 wt % were investigated. The results show that adding the element of Hg can promote discharge performance of magnesium alloy sheet in two ways: (i) adding an appropriate amount of Hg could inhibit the microgalvanic corrosion and prevent the formation of thick corrosion product film on the matrix surfaces, (ii) the second phase of Mg3Hg could activate magnesium matrix, improve peak voltage and effective discharge time. However, when the content of Hg exceeded tolerance limit, the corrosion rate of magnesium sheets would be accelerated greatly. The activation mechanism and the role of Hg in the process of corrosion product falling off were also investigated. The magnesium alloy anode sheets with Hg content between 1.65 and 2.16 wt % have the best discharge performance.