Activation, Initiation, and Growth of Electroless Nickel Coatings

This chapter attempts to develop three fundamental aspects of electroless nickel technology. First, the cleaning of the different substrates is addressed, highlighting the importance of this procedure in the final quality of electroless nickel coatings. Second, the different activation procedures for the substrates are analyzed, from classical activation with tin and palladium to the most specific procedures for each type of substrate. Finally, the morphological evolution is observed and understood on ferrous, aluminum, and magnesium substrates. For example, the typical columnar growth of these coatings or the stages of germination and coalescence of the nickel nodules is observed. This chapter is expected to provide clear and precise knowledge about the practices commonly followed by researchers for a successful formation of electroless nickel coatings on various substrates.