Effects of complexing agent on the morphology and porosity of electroless nickel deposits

Three kinds of complexing agents were selected to investigate their effects on the morphology and porosity of electroless nickel (EN) deposits on a mi ld steel substrate. The porosity of the EN coating was tested as a function of the variety of complexing agents with both an electrochemical technique and commonly used chemical spot tests. Meanwhile, the morphology and surfa ce roughness of deposits were examined by atom force microscopy (AFM). It w as found that the more stable is the nickel complex, the lower the roughnes s and the less the porosity of the coating. The reason for this is discusse d, considering the complexing agent's effect on the deposition process of E N.