Lubricated Wear Behavior of Composition-Modulated Nickel-Copper Coatings

A study has been conducted of the wear behavior of electrodeposited, composition-modulated, nickel-copper materials having two different layer spacings, 10 nm and 100 nm, under lubricated sliding conditions against type 52100 bearing steel. The materials were prepared as coatings on steel cylinders; a standard crossed-cylinder wear test geometry was used. Two lubricating liquids were used: pure paraffin oil, with and without the addition of oleic acid. Wear and friction coefficient data were obtained. Electrical measurements of the contact resistance were also made during sliding to further study the nature of the boundary lubrication film present.