Effect Of Additives On Electrocrystallization Of Nickel In The Industrial Electrolyte

In this paper,the effect of different additives and different concentration on cathode deposition potential, growth mechanism and electrochemical nucleation mechanism of nickel in the industrial electrolyte were investigated by some electrochemical tests including the liner sweep voltammetry curve, the cyclic voltammetry curve and the I-T curve. The effect of different additives and different concentration on the morphology of nickel electro deposition, grain orientation and size of grain were studied by advanced test technology such as scanning electron microscope(SEM) and X-ray diffractometer(XRD). The major result efforts of the present study are as follows:(1)Additives have a significant influence on cathode deposition potential of nickel. Saccharin sodium and 1,4-butynediol make cathode deposition potential to shift negatively. However, the composite additive makes cathode deposition potential to positively.(2)When the concentration of saccharin sodium is 1.5g/L, the cathode deposition potential absolute value is max; the concentration of the composite additive is 3.0ml/L, the cathode deposition potential absolute value is maximum, saccharin sodium and the composite additive have the same effect on the cathode deposition potential of nickel and this tend have not been found when 1,4-butynediol is added in the in the industrial electrolyte.(3)The growth mode of nickel in the industrial electrolyte is nucleation /growth. No matter whether or not add additive in the industrial electrolyte, the growth mode of nickel unchanged.(4)Additives and their concentration have a great influence on the nucleation mode of nickel in the industrial electrolyte, but nickel nucleation mode is Scharifker-Hills.(5)Without additives in the industrial electrolyte, there are many large particle grains like pyramid shape and the grain size of the deposition layer no uniform, the growth pattern of grain is the spiral dislocation growth. Adding saccharin sodium improve the compactness and flatness of deposition layer, grain size is more uniform than no additive and the shape of grain like spore. The effect of 1,4-butynediol on grain refinement is very obvious. Due to the increase of internal stress lead to micro cracks exist in the deposition layer and the crack density increases with the increase of the content of 1,4-butynediol. However, the composite additive make grain coarsen and the average size is about 2-3μm, the growth pattern of grain is the spiral dislocation growth.(6)The saccharin sodium make deposition layer have a strong diffraction peak of(200). In addition the intensity of the diffraction peak also changes with the change of the concentration of the additives...