Investigating the Effects of the current density on the properties of Ni-P-La2O3 composite coatings

Abstract

In the present study, the jet electrodeposition technique is applied to improve the wear resistance, electrochemical corrosion resistance and surface hardness of 45# steel. In order to prepare a certain concentration of La2O3 particles in the plating solution, properties of NiP -La2O3 composite coating are investigated by changing the current density from 16 A/dm 2 to 48 A/dm 2. After the experiment, physical characteristics of the workpiece, including the surface morphology, chemical composition, hardness and electrochemical corrosion resistance of the composite are analyzed by SEM, EDS and microhardness measuring instruments. Obtained results show that the best performance of the composite coating can be achieved for the current density of 32 A/dm 2. In this case, the hardness is 822.83HV0.1 and the corresponding minimum and maximum self-etching current densities are 5.61E-7 A•cm 2 and 1.46E-5A•cm 2 , respectively.