Composition Design of Ni-Nano-Cu-BTC@Ag Coatings with Low Friction and Their Intelligent Electrical Control Behavior

At present, Ni-based coatings are rarely used in the field of voltage control friction because of their poor antifriction, wear resistance, and conductive properties. Therefore, in this paper, Cu-BTC@Ag nanocrystals were used to enhance the nickel coatings, and the effect of voltage on their tribological properties was also investigated. It was found that the grains of coating were refined via the addition of Cu-BTC@Ag nanocrystals, leading to an improvement in the hardness and corrosion resistance of this composite coating. The tribological performance of nickel composite coating could be controlled under different electrical fields. With the comparison of the pure Ni-based coating, the average friction coefficient and wear volume of its composite coating with 5 wt % Cu-BTC@Ag were reduced by 7.0 and 91.8%, respectively, which showed excellent wear resistance without an applied voltage. Under the condition of 20 V, the 5 wt % Cu-BTC@Ag/Ni-based composite coating owned outstanding antifriction performance. Therefore, Cu-BTC@Ag played an intelligent role in regulating the friction of Ni-based coatings under an external voltage. It is due to the accumulation of Cu-BTC@Ag nanocrystals on the surface of the coating under the action of voltage, which played the role of supporting load and effectively reducing wear.