Tribological testing and optimisation of electroless Ni‐P coatings based on Taguchi method and grey relational analysis

This paper presents an experimental study of tribological characteristics of electroless Ni‐P (EN) coatings and optimisation of coating process parameters based on Taguchi method coupled with grey relational analysis. A grey relational grade obtained from the grey relational analysis is used as performance index to study the deposition of EN coating with multiple tribological performance characteristics. Experiments are carried out by utilising the combination of process parameters based on L27 Taguchi orthogonal design with four process parameters, namely, bath temperature, concentration of nickel source solution, concentration of reducing agent and annealing temperature. It has been observed that concentrations of nickel source solution and bath temperature are the most significant parameters for controlling the friction and wear behaviour of EN coating. The surface morphology, composition and wear mechanism of coatings are also studied with the help of scanning electron microscopy, energy dispersed X‐ray analysis and X‐ray diffraction analysis.