A study of B4C‐SiC composite for self‐lubrication

A B4C‐SiC composite without annealing and two B4C‐SiC composites followed by annealing at 1000℃ and 1200℃ for 1 hour in air, respectively, were prepared. The tribological properties of the three composites were evaluated by sliding against SiC balls at room temperature under unlubricated conditions. The B4C‐SiC composite can obtain lower friction coefficient by annealing at 1000℃, whereas the friction coefficient of B4C‐SiC composite annealed at 1200℃ was significantly increased. The cause for this difference was ascribed to different surface compositions after annealing. The mechanism of self‐lubrication of the B4C‐SiC composite was the formation of H3BO3 layer.