Effect of current density on properties of Ni-P-Al2O3-PTFE nanocomposite coatings by jet electrodeposition

In order to achieve the purpose of protection and strengthening of material surface, Ni-P-Al2O3-PTFE nanocomposite coatings were prepared by jet electrodeposition in this work, and the effect of current density on the comprehensive properties of nanocomposite coatings was studied. The microstructure, surface morphology, and element content of the composite coatings were analyzed by X-ray diffractometer (XRD), scanning electron microscope (SEM), and energy dispersive spectrometer (EDS). The mechanical properties of the nanocomposite coatings were evaluated using Vickers hardness tester, friction and wear tester, and nanoindenter. The results show that with the increase of the current density, the surface quality and comprehensive properties of the composite coatings present a trend of improving first and then reducing. When the current density is 10 A/dm(2), the nanocomposite coating has good surface morphology, the content of Al and F elements reaches the maximum value of 2.54 wt.% and 0.78 wt.%, and the deposition rate reaches the maximum value of 35.39 mu m/h, the microhardness reaches the maximum value of 562 HV, the average friction coefficient and wear scar width reach the minimum value of 0.1513 and 112.22 mu m, the elastic recovery ratio (h(e)/h(max)) and the ratio of microhardness to Young's modulus (H-3/E-2) reach the maximum values of 0.25 and 0.033, and the composite coating has excellent wear resistance and toughness at this time. The development of this research can provide theoretical and technical support for the preparation of multi-component nanocomposite coatings with excellent performance by jet electrodeposition.