RESUMO
The Co were incorporated into the Ni-W/diamond nano-composite coatings by introducing CoSO4 in the aforesaid plating bath. The effects of the Co content in the electrodeposit on microstructure and mechanical properties were analyzed. The morphology and the composition of the deposits were investigated by means of SEM and EDS, respectively. The Co content in the coatings increases progressively upon increasing the amount of CoSO4 in the plating bath. The addition of small amount of CoSO4 in the plating bath tends to enhance the hardness and wear performance of the Ni-W/diamond nano-composite coatings. While the amount of CoSO4 beyond 0.2 g/L in the plating bath, the hardness and the wear resistance of the coatings decrease sharply.
RESUMO
Nickel-tungsten (NiW) coatings were fabricated by electrodeposition method with varying quantities of sodium dodecyl sulphate and sodium bromide to examine the effects of the aforesaid additives on the coatings. The obtained nanocoatings were studied by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and hardness tester. The hardness, tungsten content and grain size attained a maximum value at current density of 0.15 A/cm²,0.1 A/cm² and 0.1 A/cm², respectively. There was a pronounced impact of both the additives on the microstructure and morphology of the coatings. According to results, there are considerable difference in terms of the impact caused by the additives to the tungsten content, hardness and grain size of the coatings. The obtained results suggest that hardness of coatings is mainly contributed by W content in the deposits.