In order to obtain BCN films that can work in a wide temperature range,amorphous BCN films and BCx films were prepared by closed field unbalanced magnetron sputtering.The influence of nitrogen content on the tribological and mechanical properties of the film was studied by adjusting the N2 flow rate.The results show that the hardness and elastic modulus of the BCN film decrease with the increase of the N2 gas flow rate.In a wide temperature range from room temperature to 600 ℃,the BCN film prepared when the N2 flow rate is less than 20 sccm has a more stable friction coefficient and lower wear rate,and has better tribological properties than the BCx film.With the doping of N elements,the mechanical properties of BCN film decrease,but the tribological properties are significantly improved.Therefore,by regulating the mechanical and tribological properties of BCN film through changing the nitrogen content,BCN film is expected to achieve friction reducing and lubrication in a wide temperature range.