Quaternary alloy of Ni-Zn-Cu-P from hypophosphite based electroless deposition method

Hypophosphite based electroless quaternary Ni-Zn-Cu-P alloy deposition was done on pure iron substrates by using copper and zinc salts as additive in plating bath solutions at various plating bath pH. Using X-ray diffraction (XRD) analysis, Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX), the crystallinity, surface morphology and composition of Ni alloys were observed and also determined. The corrosion behavior of Ni alloys was studied using electrochemical polarization curve measurements in 3.5% NaCl solutions and compared with ternary alloy of Ni-Cu-P and Ni-Zn-P respectively. It was revealed that the increase of pH decreased phosphorous, zinc and copper in the Ni alloy. From polarization curve measurements, it is believed that the inclusion of Zn in the alloy has a significant effect on corrosion performance of Ni alloys.