Effect of pyridine on the electrocrystallization and corrosion behavior of Ni–W alloy coated from citrate–ammonia media

The effect of pyridine on coatings morphology, composition and crystallographic orientation during electrodeposition of Ni–W layers from citrate–ammonia media onto copper substrate was investigated using SEM/EDS and XRD. The obtained Ni–W–Pyr layers were smoother, more compact and with finer grain size. Furthermore, deposited film gives good crystalline structure with (2 0 0), (1 1 1) and (3 1 1) preferred orientations. Corrosion mechanisms and stability in 5 h of immersion into 3% NaCl of various coatings were discussed in the consideration of electrical conductivity, microhardness, porosity, and inhibition efficiency.