Effect of Nd addition on the corrosion behavior of SAC305 solder alloy

This work studied the effects of Nd on the corrosion behavior of a SAC305 alloy. The results show that the undercooling in solidification process decreases to 1.5–2.5 ℃ with Nd addition. The corrosion resistance of the solder with Nd is markedly enhanced, which is reflected in the following aspects: (1) the potential difference between IMCs and Sn drops to 14.4 mV and lessens the galvanic corrosion sensitivity; (2) the thickness of the passivation film increases; and (3) the proportion of SnO2 in corrosion product layer in the pseudopassivation region increases. Specifically, 0.05 wt% Nd addition can provide the best improvement effects.