Development of lead free pulse electrodeposited tin based composite solder coating reinforced with ex situ cerium oxide nanoparticles

Abstract Pure Sn and Sn–CeO 2 nanocomposite films have been pulse electrodeposited from an aqueous electrolyte containing stannous chloride (SnCl 2 ⋅2H 2 O) and triammonium citrate (C 6 H 17 N 3 O 7 ). The codeposition is achieved by adding different amounts of ball milled CeO 2 nanopowders (1–30 g/L) with a mean particle size of ∼30 nm to the electrolyte. Microstructural characterizations have been carried out by X-ray diffraction analysis, scanning electron microscopy coupled with an energy dispersive spectroscopy, and transmission electron microscopy. The microstructural observations show that a uniform microstructure is obtained at a concentration of ∼6 wt% CeO 2 in the deposits corresponding to 15 g/L CeO 2 in electrolyte. Thus, incorporation of an optimum amount of CeO 2 in a composite provides better mechanical, and wear and friction properties, without sacrificing the electrical resistivity significantly.