Corrosion investigations on lead-free solder alloys in MgCl2 and NaCl solutions

This study presents the corrosive properties of five various lead-free solder alloys (including Innolot and SAC305) at room temperature. The measurements were carried out in a 0.38 wt % magnesium chloride solution and in various NaCl solutions: 0.1mM, 1mM, 10mM, 500mM and saturated one. After linear sweep voltammetry (LSV) measurements the solder alloys were also investigated by scanning electron microscope (SEM) and energy-dispersive x-ray spectroscopy (EDX) methods. The LSV results showed that the corrosion resistance of Innolot was significantly lower compared to the other ones, such as SAC305 solder alloy in case of MgCl₂. Moreover, according to the EDX results bismuth and antimony were detected in the products of Innolot using MgCl₂ solution. In case of NaCl measurements, the results showed that Innolot has higher corrosion resistance in case of low, medium and saturated NaCl concentrations, while this result was changed at 500mM NaCl concentration level.