Effect of Rough-Surfaced Diamond Content on the Microstructure, Tribological Behavior, and Corrosion Resistance of Ni/Diamond Composite Coatings

This study fabricates certain Ni/diamond composite coatings using a coelectrodeposition method and then evaluates the effect of diamond content on the morphology, phase structure, microhardness, wear, and corrosion resistance of such coatings, while exploring their tribological and anticorrosion mechanisms. It is demonstrated that the addition of diamond can change the preferred orientation of Ni from (200) to (111), and its texture coefficient value can be boosted from 23.3% to 64.4% with the increase of diamond content. In the experiment, at a diamond content of 3 g L-1, the deposited diamond particles are more and evenly dispersed across the composite, with the microhardness of nickel-based coatings reaching an optimum value of 613 HV. In addition, the coefficient of friction is reduced to a minimum value of 0.627, while the wear rate is kept at only 1.79 x 10(-5) mm(3) Nm(-1), indicating a high wear resistance. Electrochemical test results demonstrate that the Ni/diamond composite coatings produced at 3 g L-1 create the maximum charge transfer resistance (5429.3 & omega; cm(2)) and the minimum corrosion current density (2.19 & mu;A cm(-2)), features that can deliver the best corrosion resistance.