Morphology and Microhardness of Nickel Electroformed under Vacuum-Degassing Conditions
Ni deposits were prepared from a nickel sulfamate type electrolyte bath under vacuum-degassing and temperature-gradient conditions without any additives. Morphology and microhardness of the deposits obtained at the current density of 1A/dm2, 3A/dm2, 5A/dm2 and 7A/dm2 were examined and analyzed. Experimental results showed that the deposits obtained under vacuum-degassing and temperature-gradient conditions exhibited fewer pinhole defects and finer grain size comparing with those formed under conventional deposition conditions, and that the microhardness of the deposits was greater than that from conventional deposition conditions without additives while lower than that from conventional deposition conditions with additives. Under the vacuum-degassing conditions, the electroforms had remarkably smoother surface with fewer void defects and finer grain size, and considerably microhardness.
Bo Zhao, Guanglin Wang, Wei Ma, Zhibo Yang and Yanyan Yan
P. M. Ming et al., "Morphology and Microhardness of Nickel Electroformed under Vacuum-Degassing Conditions", Key Engineering Materials, Vol. 455, pp. 495-498, 2011