This paper reports a phenomenon that the grain orientation gradually evolves to (220) with the deposition current density increasing when preparing nanoparticles reinforced nickel-based composite coatings by jet electrodeposition (JED). During the preparation of Ni-SiC composite coatings, the deposition current density increases from 180 A/dm2 to 220 A/dm2, and TC(220) gradually increases from 41.4% to 97.7% correspondingly.
The Ni-SiC composite coating with highly preferred (220) orientation has superior corrosion resistance and adhesion force. With the increase of TC(220), the surface roughness is reduced from Ra1.210 μm to Ra0.119 μm, the self-corrosion potential increases from -0.747 V to -0.477 V, the corrosion current density decreases from 54.52 μA·cm2 to 2.76 μA·cm2, the diameter of corrosion pits that after 10 days of immersion in 3.5 wt% NaCl solution decreases from 3.3~22.2 μm to 153~260 nm, and the adhesion of the coating is increased from 20.5 N to 61.6 N.
The research results can provide theoretical and technical support for the preparation of new composite coatings with high efficiency, low cost, high adhesion and strong corrosion resistance.