Evaluation and Comparison of Tribocorosion Behavior of Ni-P and Ni-B Electroless Coatings

In this research, tribocorrosion behavior of Ni-P and Ni-B electroless coatings was investigated. Ni-P containing 10-12wt.%P and Ni-B containing 0.2-0.5 wt.% were deposited on steel substrates by electroless plating. Electrrochemical behavior of the coating was studied in 0.5 molar Na2SO4 solutions by potentiodynamic polarization technique. Wear behavior of the coatings was evaluated by ball-on-disc test and their tribocorrosion behavior was also investigated by reciprocating method conducted in an electrochemical cell. The results showed that corrosion and wear resistance of Ni-P coating were higher than that of Ni-B coating, but friction coefficient of Ni-B coatings was lower than that of Ni-P coatings. Also, the tribocorrosion test demontrated that the effect of corrosion on wear in Ni-P coating was more than that of Ni-B coating and thus, the volume loss after wear of Ni-P coating has been increased rather than that of Ni-B coating in anodic potential.