Corrosion Study of Electroless Ni-P-W Coatings Using Electrochemical Impedance Spectroscopy

Abstract

The present study investigates the significance of different coating process parameters on the corrosion behaviour of electrolessly deposited NiP -W coatings on mild steel substrate. The process parameters considered are concentration of nickel source, concentration of reducing agent, concentration of tungsten source and annealing temperature. The corrosion characteristic is evaluated by electrochemical impedance spectroscopy technique. The responses considered are charge transfer resistance and double layer capacitance. The Taguchi technique coupled with grey analysis is employed to find out the optimum combination of the process parameters for better corrosion resistance. Analysis of variance (ANOVA) reveals the contribution of the process parameters on the corrosion property of NiP -W coating. Finally a validation test is performed to justify the experimental result. The microstructure of the surface is studied by scanning electron microscopy (SEM); energy dispersive x-ray analysis (EDX) reveals the chemical composition and the x-ray diffraction analysis (XRD) is used to identify the phase transformation behaviour of the coating.

Investigation of Wear Behavior of Electroless Ni-P-W Coating under Dry and Lubricated Conditions Using RSM and Fuzzy Logic

“…The best corrosion resistance is achieved at lower scanning velocities [39,40]. It has been used the design of experiments and Taguchi based Grey relational analysis for the optimization of tribological testing parameters for minimum friction and wear, while optimization of coating deposition parameters for improving corrosion resistance of electroless Ni-P-W coating has been carried out extensively by Roy and Sahoo [41,42]. A parametric combination of 50N applied normal load, 70 rpm roller speed and 5min test duration has been reported to yield minimum friction and wear of the coatings on a block-on-roller multi-tribotester [41].…”

“…A parametric combination of 50N applied normal load, 70 rpm roller speed and 5min test duration has been reported to yield minimum friction and wear of the coatings on a block-on-roller multi-tribotester [41]. From electrochemical impedance spectroscopy study in 3.5% NaCl solution, the best corrosion resistance is seen for a coating bath composition having 30 g/L nickel sulphate, 17 g/L sodium hypophosphite, 25 g/L sodium tungstate and an annealing temperature of 600 °C [42]. Optimum deposition of tungsten and phosphorus content of the coatings using orthogonal arrays by considering plating bath parameters such as concentration of sodium hypophosphite, sodium citrate, bath temperature, pH and stabilizer has been reported by Shu et al [43].…”

“…From an extensive review of literature, it seems that the research concerning electroless Ni-P-W coating is mainly directed towards the investigation of surface morphology, microstructure, corrosion resistance, microhardness, wear resistance and friction behavior. The effect of different heat and surface treatments on the same has also been studied, while the tribological behavior has been investigated mostly under dry sliding condition [31][32][33][34][35][36][37][38][39][40][41][42][43]. Investigation of tribological behavior of EN coatings under lubricated condition is seen to be mostly concentrated around Ni-P binary alloy coatings and its composite variants [13,[14][15][16][17][18].…”

An Experimental Approach for Optimizing Coating Parameters of Electroless Ni-P-Cu Coating Using Artificial Bee Colony Algorithm

“…The choice of the third particle depends on the desired property. Ternary Ni-P coatings, such as Ni-Cu-P [2, 3], Ni-W-P [4–8], Ni-P-PTFE [9, 10], Ni-P-SiC [11, 12], Ni-P-Al 2 O 3 [13, 14], and Ni-P-TiO 2 [15–17], have been investigated by different researchers. Among the ternary Ni-P alloy coatings, the electroless Ni-Cu-P alloy presents superior corrosion resistance and thermal conductivity than others [18–23].…”

Parametric optimization of corrosion and wear of electroless Ni-P-Cu coating using grey relational coefficient coupled with weighted principal component analysis

“…The choice of the third particle depends on the desired property. Ternary Ni-P coatings, such as Ni-Cu-P (Yu et al 2002;Aal and Aly 2009), Ni-W-P (Palaniappa and Seshadri 2008;Balaraju et al 2006a;Balaraju et al 2006b;Roy and Sahoo 2013;Roy and Sahoo 2012), Ni-P-TiO 2 (Abdel Aal et al 2008;Chen et al 2010;Novakovic and Vassiliou 2009), Ni-P-Al 2 O 3 (Alirezaei et al 2007;Balaraju et al 2006c), Ni-P-PTFE (Ramalho and Miranda 2005;Huang et al 2003) and Ni-P-SiC (Lin et al 2006;Jiaqiang et al 2006), have been prepared by electroless deposition. Among these ternary Ni-P alloy coatings, the electroless Ni-Cu-P alloy presents more superior corrosion resistance and thermal conductivity than the others (Liu et al 2010;Valova et al 2010;Liu and Zhao 2004;Wang et al 1992).…”