| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2018) | |
| Thin Films | Tuesday Sessions |
| Session TF-TuP |
| Session: | Thin Films Poster Session I |
| Presenter: | Yuankai Li, State Key Laboratory of Superhard Materials, Key Laboratory of Automobile Materials of MOE, and School of Materials Science and Engineering, China |
| Authors: | Y. Li, State Key Laboratory of Superhard Materials, Key Laboratory of Automobile Materials of MOE, and School of Materials Science and Engineering, China C. Hu, State Key Laboratory of Superhard Materials, Key Laboratory of Automobile Materials of MOE, and School of Materials Science and Engineering, China |
| Correspondent: | Click to Email |
High wear-resistant conductive coatings have recently attracted increasing interest owing to their technological importance in the fields of high-speed railways, artificial joints and electrode materials. However, wear-resistance and conductivity of materials are a dilemma from the perspective of structures and chemical bonds. Thus, developing ideal wear-resistant conductive coatings remains a significant challenge. Here, we propose a novel strategy to design wear-resistant conductive coatings: a transition metal nitride is selected as a base, and its wear-resistance and electrical conductivity are simultaneously improved by doping transition metals or noble metals to form a solid solution structure. The new strategy is demonstrated to be practically feasible and effective by two experiments: doping tantalum and silver into hafnium nitride films. Doping with tantalum and silver can improve wear-resistance and conductivity of hafnium nitride films due to the formation of solid solution structures. The conductivity and wear-resistance of the silver precipitated Hf-Ag-N supersaturated solid solution are higher than those of the Hf-Ta-N solid solution, which is attributed to not only the solid solution strengthening effect but also the effects of precipitate silver including the precipitation strengthening, self-lubrication and additional conductivity enhancement. Combining a series of experiments with first-principle calculations and Drude-Lorentz fitting, we have proved that the formation of solid solution structures can achieve both wear-resistance and conductivity enhancement, apart from well-known strength enhancement. This work provides new insights in designing hard, wear-resistance yet high-conductivity coatings.