Research on the coating formation of Al-induced electroless plating on metallic surfaces.

According to the design concept of hollow metallic microlattices, the quality of the coating has a considerable influence on the performance of the material. To avoid the effect of by-products in the coatings, we have chosen the Al-induced electroless plating method to respond to the composition design of this material. In this paper, the coatings formation process of Al-induced electroless plating on the metallic surface is systematically investigated. The coatings created by Al-induced electroless plating were characterized by surface morphology, XRD patterns, and electrochemical potential. Subsequently, the deposition process of elements on the metallic substrate was simulated by molecular dynamics. Finally, the surface morphology changes of coatings were observed at different plating times to verify the simulation results. The results indicate that the four kinds of coatings are each composed of a single metal element (copper, cobalt, nickel, and iron) with no by-products. Based on the results of morphology changes of the coatings and the deposition simulation, the overall formation process of Al-induced electroless plating is described. The deposition of coatings has the characteristics of preferential growth and aggregate growth. The metal atoms that are generated from the reaction of the reducing electrons with the target metallic ions in the solutions are deposited on the substrate surface as the primary cores. The reducing electrons are provided by the dissolution of Al foil. With the increase in the number of generated metal atoms, multiple atomic clusters form in the areas of the primary cores. These clusters develop at various scales on the substrate surface, forming irregular particles. Eventually, coatings are formed completely with uniform particle sizes. [ABSTRACT FROM AUTHOR]