Morphology and Microhardness of Nickel Electroformed under Vacuum-Degassing Conditions

Abstract

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.

The properties and the effect of operating parameters on nickel plating (review)

“…Recently, many investigations have been made on electroforming. Ming et al (2011) investigated the feasibility of a new micro-electroforming technique. A series of experiments were performed using special equipment, developed by the authors, followed by the evaluating the surface morphology of nickel microelectroforms using a scanning electron microscope (SEM).…”

“…Further, the bipolar RS phenomenon can be explained by the voltage-polarity-dependent movement of oxygen ions near the interface. Ming et al (2011) prepared Ni deposits from a nickel sulfamate type electrolyte bath under vacuum-degassing and temperature-gradient conditions without any additives. Morphology and micro-hardness of the deposits obtained at the current density of 1, 3, 5 and 7A/dm 2 were examined and analyzed.…”

Research on Cathode Chronopotentiograms and Interelectrode Resistance during Vacuum Boiling Electroforming

“…Therefore, our research group developed an unconventional electroforming process, electrolyte vacuum boiling electroforming, by introducing vacuum degassing technology [3,4] and surface boiling [5] technology into the electrodeposition process [6]. Our studies have shown that the electrolyte vacuum boiling electroforming process can generate the components with markedly improved surface quality (almost no pinholes and nodule) and desirable microstructures with fine grains and good compactness [7][8][9][10][11]. To explore the mechanisms determining the favorable effects, this paper focuses on analyzing cathodic potential and interelectrode resistance of the electrolyte vacuum boiling electroforming process carried out under different reduced pressure and cathode temperature.…”