Influence of lower current densities on the residual stress and structure of thick nickel electrodeposits

Abstract

Thick Ni electrodeposits, with thicknesses ranging from 18 to 90μm, have been produced from sulfamate baths using very low current densities (1.5–5mAcm−2). Increasing grain sizes, with a corresponding decrease in the hardness values, and more columnar grain morphologies were observed with increasing current densities in the deposits. The anisotropy in the mechanical properties of the deposits were found to correlate strongly with the deposit texture, where the change from a <101> dominated orientation at 1.5mAcm−2 to a <001> orientation at the higher (5mAcm−2) current density led to a corresponding decrease in the indentation modulus values for the respective Ni films. The residual stress values measured in the deposits (75–136MPa) were found to be comparable to literature values of deposits plated at higher current densities, which rules out any potential advantage from the use of such low current densities for producing lower residual stresses.