Influence of sputtering power on components and mechanical properties of boron carbide films

Boron carbide films were fabricated by radio frequency magnetron sputtering at different sputtering powers. The structure and components of the boron carbide films were characterized by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Using MTS Nano Indenter XP with CSM method, the hardness and modulus of the boron carbide films were analyzed. The results show that B prefers to combining with C to form BC bond as the RF power increases. When the sputtering power reaches 250 W, the number of BC bonds is the most, and the atomic concentration ratio between B and C reaches to the maximum of 5.66. Both the hardness and modulus of the boron carbide films increase firstly and then decrease with the sputtering powers increasing. Both of them reach to the maximum of 28.22 GPa and 314.62 GPa, respectively.