The Influence of Electrodeposition Parameters on Microhardness and Deposition Rate of Nanocrystalline Ni Coatings

Nanocrystalline nickel(nc Ni) coatings were produced by adopting pulse current deposition method and their microstructure and microhardness were investigated through using a high resolution transmission electron microscopy and a microhardness tester.The results show that the microhardness of nanocrystalline nickel increases and then decreases as the current density and content of C7H4NO3SNa ·2H2O increase.At the same time,the microhardness reaches maximum when the content of C7H4NO3SNa ·2H2O is 10 g/L and the current density 10 A/dm2.It proves that the relationship between microhardness and mean grain sizes approximately is consistent with the Hall-Petch function.And the electrodeposition rate increases as the current density rises;the addition of C7H4NO3SNa ·2H2O results in the increase in deposition rate,but the continued increase in density has minimal effects on deposition rate.