Investigation on properties of the TiSiN/TiSi-diamondlike carbon multilayer coatings prepared by hybrid deposition technique

In this research, the thermo-mechanical characteristics of TiSiN coatings and the self-lubricating attributes of elementally doped diamondlike coatings (DLCs) were utilized. Multilayer coatings composed of TiSiN and TiSi-DLC with varying modulation periods were applied to tungsten carbide substrates through the combined deposition method of high-power impulse magnetron sputtering and multiarc ion plating. The present study investigated the influence of modulation period on the microstructure, mechanical characteristics, and tribological properties of multilayer coatings. All TiSiN/TiSi-DLC multilayer coatings exhibit a preferred (111) orientation with an average grain size of less than 10 nm. The TiSiN sublayer consists of a two-phase composite structure, with amorphous SiNx dispersed within TiN grains, while the TiSi-DLC sublayer is a three-phase composite structure composed of TiC, SiC, and amorphous carbon. The multilayer design significantly enhanced the coating’s mechanical properties, including its hardness and modulus of elasticity. The TiSiN/TiSi-DLC coating showed the best mechanical and tribological properties at the modulation period of 900 nm, i.e., a high hardness of 33.2 GPa, a low coefficient of friction of 0.33, and a low wear rate of 3.6 × 10−5 mm3/N m.