Role of CTAB surfactant on electroless Ni–B deposition and its mechanical and corrosion behaviour

ABSTRACT The influence of the Cetrimonium bromide (CTAB) surfactant on the mechanism of electroless Ni–B deposition, corrosion, and scratch resistance of the resulting coatings was studied. Effect of different concentration of the surfactant on deposition rate and surface morphology was studied using SEM. Finally, the effect of an optimized concentration of CTAB surfactant on the surface chemistry, corrosion, and scratch resistance of the Ni–B coating was analysed using GDOES, potentiodynamic polarization, salt spray test, XPS, scratch test, SEM, and EDS. It was found that the CTAB surfactant increases the mass transfer and deposition rate of the coating. Adding CTAB surfactant in electroless solution significantly improves corrosion resistance by eliminating the pits formation at the surface and decreasing the number of defects at the interface which finally improves the formation of stable passive layer. Additionally, the highest scratch resistance was obtained when CTAB surfactant was added into the electroless Ni–B plating bath.