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

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.