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

Pure Sn and Sn-CeO2 nanocomposite films have been pulse electrodeposited from an aqueous electrolyte containing stannous chloride (SnCl2 center dot 2H(2)O) and triammonium citrate (C6H17N3O7). The codeposition is achieved by adding different amounts of ball milled CeO2 nanopowders (1-30 g/L) with a mean particle size of similar to 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 similar to 6 wt% CeO2 in the deposits corresponding to 15 g/L CeO2 in electrolyte. Thus, incorporation of an optimum amount of CeO2 in a composite provides better mechanical, and wear and friction properties, without sacrificing the electrical resistivity significantly. (C) 2013 Elsevier B.V. All rights reserved.