Hardness and structure of nickel electrodeposited from its sulphate and acetate salts in a 5mol.%N-methylformamide-water mixture

Abstract

The electrodeposition of nickel from its sulphate and acetate salts in a 5mol.%N-methylformamide-water mixture was carried out. The deposits obtained from the sulphate bath were milky in appearance and hard with a nodular structure, whereas those from the acetate bath were extremely bright but cracked and soft. The cracked and brittle structure of the deposits obtained from the acetate bath is attributed to the adsorption and/or codeposition of hydrogen and its subsequent diffusion outwards. The comparatively low ionization in the acetate bath may be due to complex formation with cosolvent molecules (N-methylformamide), which gives rise to a fine-grained bright deposit. © 1984.