Role of cerium in microstructure and corrosion properties of Sn-1.0Ag solder alloys

An alloying element of Sn-1.0Ag-based solder alloy can provide a great opportunity to improve their solder properties and increase its capacity for corrosion resistance. We have developed Sn-1.0Ag-xCe solder alloys consisting of a range of cerium contents from 0 to 0.5 wt% in the production of the refinement and continuation of the precipitates, as well as the reduction in grain size of the alloy microstructures. An increase of cerium addition supported on corrosion resistance exhibited relatively improved pitting potential, film and charge transfer resistances which particularly promoted the formation of passive film, resulting in an improvement of pitting resistance.