Lubricated sliding wear behaviour of Ni–P–W multilayered alloy coatings produced by pulse plating

Abstract The lubricated sliding wear behaviour of Ni–P–W multilayered alloy coatings sliding against hardened steel discs was studied, in a pin-on-disc set-up. The multilayered coatings had been deposited on mild steel pins by pulse plating and they consisted of ternary Ni–P–W layers of high and low W content. The wavelengths studied were 6, 200 and 2000 nm and the total thickness of the coatings was 25 μm approximately. Using a range of normal loads between 2 and 110 N and a range of sliding speeds between 14 and 90 cm/s, the Stribeck curve of the system was constructed, indicating the various lubrication regimes. The wear mechanisms in each lubrication regime were studied and in mixed lubrication regime, the effect of normal load and sliding speed on wear volume and friction coefficient was also studied.