Residual stresses in electrodeposits of nickel and nickel-iron alloys

The mechanical properties of micro-hardness and interval stress, obtained using the EFCO stressometer and X-ray diffraction, have been measured as a function of bath composition, 'on/off' cycles,current density, types of plating and solution pH. The electrodeposition of nickel and nickel-iron alloy on copper and mild-steel substrates from Watts and Ni/Fe baths have been investigated, using both direct current and pulsed-current electrolysis, with various ratios of 'on'-time to 'off'-time. Distinct differences between direct and pulsed processes revealed themselves in the surface characteristics, micro-hardness data, CCE data, internal stress measurements, pH data, various current density and finally composition of the deposits. The implications of using pulse plating to control the quality of electrodeposits have been considered. (C) 1999 Elsevier Science S.A. All rights reserved.