Electrodeposited Feni-(co) P Alloy And Its Properties

Electrodeposition of multi-alloy are attractive in recent year because of their special properties. FeNi(Co)P alloy (include FeCoP and FeNiP) has outstanding soft magnetic performances. In this work, new basic baths for preparing electrodeposition of FeNiP and FeCoP alloys have been proposed, where sodium citrate was used as a complexing reagent, boric acid as a buffer reagent. It is illustrated that these plating baths can promote the content of the third element Fe in the deposits and it is easy to control the composition of alloy. The effects of bath compositions and plating conditions on the plating rate and the composition of the deposits have been explored. The mechanism of the electrodeposition of FeNiP alloy has been investigated. The crystallization behaviors and the microstructures of FeNiP and FeCoP alloys have been studied by various techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), etc. The relationship between magnetic performances of FeNiP or FeCoP alloy and plating conditions has been investigated by the vibrating sample magnetometer (VSM), and the effect of heat treatment on the magnetic performances of FeNiP alloy has also been studied. The corrosion resistance properties of the FeNi(Co)P deposit in sodium chloride solution has been examined by anodic polarization. The performance of evolution hydrogen of the FeCoP coatings has been investigated through cathodic polarization method. Main results in this dissertation are summarized as follows:1.Effect of plating conditions on the plating rate, the composition andthe structure of the multi-alloy depositsThe effects of pH of the bath, current density, etc, on the plating rate and the composition of the deposits have been studied. In certain range of pH of the bath, the increase of the bath pH will promotes the deposition, and raises the content of Fe in the deposits, while it decreases the content of P.The pH value has more influence on the surface morphology of the multi-alloys, but less influence on its structure. FeNiP and FeCoP alloys are amorphous.