Microstructure, mechanical and tribological properties of TiMoN/Si3N4 nano-multilayer films deposited by magnetron sputtering

TiMoN/Si3N4 nano-multilayer films with different Si3N4 layer thickness were synthesized using magnetron sputtering by changing the Si target current. The TiMoN/Si3N4 nano-multilayer films exhibited strong microstructure and properties dependence on the structures of Si3N4 layer. When Si3N4 layer thickness (lSi3N4) was smaller than 0.8 nm, Si3N4 layers maintained crystallization state, the as-deposited TiMoN/SiNx films exhibited much higher hardness and comparable coefficient of friction (COF) than that of MoNx/SiNx films. With the further increase of lSi3N4, Si3N4 layer transformed to amorphous state, the hardness of TiMoN/Si3N4 films decreased gradually from 29.9 to 20.1 GPa and COF increased from 0.55 to 0.72. It totally shows better tribological properties than TiAlSiN/Si3N4 nano-multilayer films as a result of incorporating molybdenum nitride.