| The ferrous alloy foil has a lot of properties such as good corrosion resistance, soft magnetic property, catalysis and low thermal expansion properties. It was took as a s special profile,whose preparation technology has become hot spot in the field of materials science and electrochemistry of this century.In this paper, the sulfate-chloride system of the electrodeposited Ni-Fe alloy foil was studied deeply by using single factor and orthogonal experiment. According to HULL experiment,process parameters of Ni-Fe alloy foil electrolyte solution were determinted. The effects of technology parameters on electrodeposition alloy foil were explored by the single factor. The technology parameters were the mole ratio of n(Ni2+)/n(Fe2+), the concentration of coordination agent, current density, temperament, pH value. The optimal experiment conditions were obtained by orthogonal experiment as followes:the mole ratio of n(Ni2+)/n(Fe2+) was 4,current density was 22A·dm-2, the solution temperature was 63℃, pH value was 3.8,and citric acid concentration was 40g·L-1.On the basis of Ni-Fe alloy foil electrolyte, the technology about electrodeposition of Ni-Fe-Cr alloy foil was studied in detail. After a large number of preliminary exploration, several key parameters were obtained,which were analyzed by orthogonal experiment.Ni-Fe-Cr alloy foil with high Cr content was obtained, the optimum technological conditions were also obtained as followes:the concentration of formic acid was 8 ml/L, current density was 14A·dm-2, temperature 30℃, the concentration of chromium sulfate Cr2(SO4)3·6H2O was 60 g·L-1.By energy spectrum analysis, The Ni-Fe foil was obtained,whose iron contentl was 27% and nickel content was 73%. In continuous Electrodeposition process, changes in the composition mass fraction was 1.14%.,Its resistance was 38～41μΩ·cm, Largest permeability was.172mH·m-1, Saturation magnetic induction wasl.093T, remanence was 0.0088T. On the whole,Ni-Fe foil has good soft magnetic properties. After repeated bending and 180°folding, Ni-Fe foil will not break, consequently it possesses good toughness and low residual stress. Experimental results showed that the solution of Ni-Fe alloy foil electrolyte had good stability,covering power and throwing power. By energy spectrum analysis, the Ni-Fe-Cr alloy foil obtained by orthogonal experimental have Cr content of 3.5%. Tafel polarization curves and EIS showed that Ni-Fe-Cr alloy foil had a better corrosion resistance than the Ni-Fe alloy foil.Through the methods of the linear potential sweep and the cyclic voltammetry, the electrochemical laws of Ni-Fe alloy foil and Ni-Fe-Cr alloy foil were explored in different conditions. The structure, morphology and hardness of the foil layer were determined by the scanning electron microscopy (SEM), X-ray diffraction (XRD), microhardness texting and other modern means. The results indicated that the two foils above were solid solution crystals with face-centered cubic, the grain size was about 10nm and the nano-crystalline structure was typical. The surface of the foil layer was bright, with on pinholes and cracks. The average hardness value of the Ni-Fe alloy foil and the Ni-Fe-Cr alloy foil were 247Hv and 450Hv, the latter foil had a higher hardness value.In our study, alloy foil was obtained by electro-deposition which compared with the traditional technology has many advantages,such as once molding, the low cost, compact organization, uniform thickness, the size and the thickness can be controled, continuous production, without the defects of holes and coarse grains and so on. At present, the industry of electro-deposition alloy foil was blank in the domestic. In this paper, theoretical significance and industrial value of the electrodeposited Ni-Fe and Ni-Fe-Cr alloy foil were explored. |
PDF Full Text Request