Investigation and optimization of SDS and key parameters effect on the nickel electroless coatings properties by Taguchi method

In this research, the influence of anionic surfactant sodium dodecyl sulfate (SDS), pH, substrate finishing, and annealing temperature on the surface morphology and hardness of the electroless nickel phosphorus (ENi–P) coatings were studied. Taguchi’s experimental design method was used. Parameters selected in three levels and L9 from orthogonal robust array design were employed. Surface roughnesses of the deposits were measured using a stylus instrument. Scanning electron microscope and x-ray diffraction analysis were implemented to study surface morphologies and phase composition, respectively. Microhardness of the ENi–P deposits was measured using a microhardness tester at three trials per sample. The results showed that addition of the SDS increases the microhardness and improves surface morphology. Finally, optimum condition was achieved as, surfactant concentration equal to 1.5 g/L, pH 5.5, substrate finishing provided with emery paper no. 2000, and annealing temperature equal to 400°C.