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

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 p lating and they consisted of ternary Ni-P-W layers of high and low W conten t. The wavelengths studied were 6, 200 and 2000 nm and the total thickness of the coatings was 25 mu m approximately. Using a range of normal loads be tween 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 lubri cation regimes. The wear mechanisms in each lubrication regime were studied and in mixed lubrication regime, the effect of normal load and sliding spe ed on wear volume and friction coefficient was also studied. (C) 2000 Elsev ier Science S.A. All rights reserved.