Electrochemical study of electroless deposition of Fe–P alloys

Fe–P deposits were prepared by electroless deposition and the inducing effect of coupled aluminum on Fe–P deposition was studied. The partial reactions of reducer oxidation and metal ions reduction in electroless deposition Fe–P bath were investigated by electrochemical investigation. In situ mixed potentials of the process for electrolytes with different pH were measured. The plating rate of iron alloys was measured gravimetrically and calculated by the deposition current density. The results show that coupled aluminum induces the Fe–P deposition by shifting the potential negatively and decreasing the polarization resistance of anodic and cathodic reaction. The test of the mixed potential theory was performed by comparison between direct experimental values of the mixed potential and plating rate with those derived theoretically from the current–potential curves for partial reactions. Due to the hydrogen evolution, the plating rate determined by electrochemical measurement is higher than the average plating rate determined from gravimetrical measurements.