Investigating the Effect of Fe2O3 on Wear Behaviour and Corrosion Resistance of Electroless Ni–P Coating with Different Fe2O3 Concentrations on AISI 4140 Steel

Abstract

In this study, Ni–P–Fe₂O₃ composite was deposited on AISI 4140 steel using different concentrations of Fe₂O₃ ranging from 0.1 to 0.5 gr/lit in an electroless bath. The phase analysis and surface morphology of the samples were characterized using X-ray diffraction and FESEM. The corrosion behavior of the coated samples was investigated in a 3.5 wt. % NaCl solution through potentiodynamic polarization. The results of the potentiodynamic test show that adding Fe₂O₃ into an electroless bath facilitates the formation of the passive layer. The results show that the coating created at a thickness of (10-16µm) had the highest corrosion resistance compared to other coated and non-coated samples. Furthermore, the results of the friction coefficients of the samples produced by powder metallurgy have decreased because Fe₂O₃ particles led to a decrease in grain size in the heat treatment of specimens and prevented excessive heat generation during the wear test; thus, the friction coefficient decreased during the test.