Process research on electroless Ni-Fe-P deposition with high depositing speed

Ni-Fe-P alloy was prepared on the surface of A3 steel by electroless plating technology. The components, structure and morphology were investigated by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and optical microscopy (OM). The deposition rate, bath stability were measured by mass increase method and palladium chloride method, respectively. The effects of the parameters (main salt, reducing agent, complexing agent, stabilizer, pH value and temperature) of the bath on the deposition rate, morphology, components and bath stability were studied. The process formula with high depositing speed, uniform coating and stable bath was obtained finally. The deposition rate was 20.2 mg·cm^-2·h^-1 and bath maintained stable when the concentration of sodium citrate and aminoacetic acid were 60 g/L and 5 g/L.