Electrochemical behaviour of lead-free Sn-In-Al solders alloys in 3.5 wt.% NaCl solution

Abstract

The corrosion properties of lead-free solder alloy can not be ignored in the field of the electronic industry. However, there is no literature on the effect of aluminium on Sn-In binary solder alloys. This study looked at the corrosion of a lead-free solder alloy in a 3.5 wt.% NaCl simulated seawater environment. Three isopleths were created with varying aluminium content in the Sn-In-Al system while maintaining Sn and In radio constant (1:1). The vacuum sealing process was used to create the samples. The corrosion resistance of this lead-free solder ware was investigated at room temperature in a 3.5 wt.% NaCl solution. Corrosion resistance improves with Al content, according to the potentiodynamic polarization test. By lowering the current density (Icorr), the inclusion of aluminium refines the microstructure. It enhances the corrosion resistance of Sn-In-Al solder alloys, resulting in high resistance of the passive layer produced by lowering the current density (Icorr). Scanning electron microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDS) was used to analyze of surface morphology of the non-corroded and corroded Sn-In-Al solder alloys. Intermetallic compound (IMC) of non-corroded and corrosion products on the surface corroded solder alloys were studied using X-ray diffraction (XRD). According to XRD analysis, the composition of corrosion products altered as the aluminium content changed, forming phases such as Sn3O(OH)2Cl2, oxides, and chlorides of Sn.