Sliding-Wear Properties of Electro-Deposited Films with Cu and Pulse-Plated Ni Multi-Layers

Abstract

The purpose of the present study is to investigate the effect of component layer geometry on wear resistance in multilayered structures consisting of soft Cu layers and hard nanocrystalline Ni layers, which were fabricated by electrodeposition. Pulsed-potentials were applied only during the nickel layer deposition to obtain the nanocrystalline Ni microstructure. We prepared the multilayers with various component layer thicknesses and various ratios of the Ni to Cu layer thicknesses. Pulse-plated nickel films without Cu layers were also prepared for comparison. The formation of nanostructured grains was recognized in the pulse-plated nickel using transmission electron microscopy (TEM). Among the multilayered films prepared in this study, the multilayer with the nanocrystalline nickel layers of 190 nm thickness and the Cu layer of 10 nm thickness revealed the best wear resistance. The weight-loss rate and the worn depth of this multilayered film were approximately half of those measured in the nanocrystalline nickel film without the Cu layers at the vertical loads of 10 N and 20 N. These results suggest that the periodic insertion of thin Cu layers can improve the wear property of nanocrystalline nickel film.

Weight-loss rates of the nanocrystalline-Ni/Cu multilayered films subjected to sliding wear at different pin loads.