Abstract
Nickel was electrodeposited from nickelsulfamate dissolved in N-methylformamide (HCONHCH3)-water mixtures of varying compositions. The deposit obtained from mixed solvents was found to be better with respect to quality, efficiency and hardness and with lesser defects in surface structure, compared to conventional nickel deposits. These are attributed to the structural changes in the solvent mixtures. Bright, smooth and hard deposits were obtained from 5 mol% NMF-water mixture and hence the influence of current density, temperature and addition of boric acid on cathode current efficiency, microhardness and microstructure was investigated in this system. Presence of boric acid increases the rate of nickel deposition, inhibits the outgrowth of crystals, thus enhancing the grain refinement which is attributed to its catalytic influence.
