Modelling of surfactants and chemistry for electroless Ni-P plating

Abstract

In this work, the effects of the chemical formulation in an electroless nickel phosphorus electrolyte on the physical and mechanical performance of the obtained coating were evaluated. The study paid particular attention to the concentration and type of surfactant (anionic, cationic and nonionic) but also investigated the effect of pH and concentration of sodium hypophosphite in the electrolyte. A three-level Box-Behnken factorial design related to response surface methodology was employed to model the effect of the mentioned parameters and optimize the properties of the coating. Two models fitted with experimental data obtained from microhardness and thickness measurement of the Ni-P coatings. The optimum conditions were determined at pH=5 with 32 g/L sodium hypophosphite and 1.5 g/L anionic surfactant. According to the derived models this formulation would give a Ni-P coating with microhardness of 1080 Hv and thickness of 23 µm.

Recent advances in electroless nickel‑boron coatings

“…The increase of plating rate is attributed to electrostatic interactions between individual charged surfactant molecules and the oppositely charged Ni particles [240]. The use of such compounds in EN-P also enhances the adhesion of the coating on the substrate [241], increases the hardness of coatings [242,243], and improves the wear resistance [244], and can help with the elimination of hydrogen bubbles during the deposition process, thus limiting the risk of micropitting and leading to an increase of corrosion resistance [238,[245][246][247].…”

Effect of pH on the characteristics of electroless Ni-P coatings

“…Surfactants may also be added to the Ni-P bath, which can influence the properties of the coatings, and the conditions of deposition [27][28]. Chen et al investigated the effects of using different types of surfactants.…”

Erosion-Corrosion Behavior and Mechanism of Heated Electroless Ni–P Coating under Flow

“…11,12) In recent years, electroless NiP coating, NiP based composite coating as well as their properties were extensively studied. 13,14) P. Shoghi, et al 15) introduced that the corrosion resistance of the magnesium alloy was strongly improved after coating NiP. B. K. Choi, et al 16) investigated the performance of electroless NiP coating/carbon fibers heated at different temperature.…”