Study On Preparation And Character Of Nano-iron Coating By Electrodeposition

In recent years, scientific researchers have paid more attention on the preparation of nanocrystalline iron, whose excellent characters have played a big role in many fields, such as disposing of sewage, medical treatment, military material and so on. Among the methods, electrodeposition is an easily-control, high efficiency one, and its advantage surpass many others, like physical and chemical one.In this paper, the influence on character of solution and plating is studied, which is by the variations of solution parameters, the pattern of magnetic field and the selection of pulsed current parameters, especially on the nano-dimension of plating. And finally the nanocrystalline iron plating with 15nm is obtained.The solution parameters selection is a foundation of electrodeposition, which make an effect on the nano-dimension of plating directly. Addictive can improve the quality of solution and plating. Through study, standard solution is chosen, whose parameters are: [FeCl·4HO]=400g/L, T=30℃, pH=1-1．5, [saccharin]=4g/L, [sodium kauryl sulfate]=0．05g/L.Different kinds of magnetic field are acquired by different modes of installment of coil and coating bath. The magnetic fields, which are perpendicular or parallel to electric fluxline can make different results on solution and plating: the magnetohydrodynamic (MHD) effect caused by the Lorentz force can be observed under the perpendicular magnetic field; iron is ferromagnetic, so it can be affected by the field gradient force under the parallel magnetic field. The perpendicular magnetic field is benefit for the desperibility of solution, but is harmful to the decrease of iron grain; the parallel one is superior to the perpendicular in those two sides, and with which increases, the iron grain decrease remarkably.The smooth, pliable, hard, micro-grain iron plating can be acquired by pulsed current. Attributes to the break time in pulse electrodeposition, the thickness of diffusion layer decreases, which makes huge instantaneous current density acquired and the iron grain reduced.Through XRD, we can find that the construct of plating do not be changed in experiment. On the XRD diagram, the diffracted peak widen at the high angle, which prove the iron grain decrease. But the decreasing do not amplify the hardness of plating. When the decreasing reach a certain degree, un-Hall-Petch relationship is found, in which the modulus is related to electrodeposition condition.