Mechanical and tribological properties of h-BN/ZrO2/SiC solid-lubricating ceramic composites

h-BN/ZrO2/SiC solid-lubricating ceramic composites were prepared by spark plasma sintering method. The mechanical and tribological properties were further investigated. Mechanical properties declined with increasing the content of h-BN, meanwhile, the friction coefficient decreased from 0.78 +/- 0.11 to 0.32 +/- 0.05 at room temperature with the content of h-BN increasing from 10 to 70 vol%, while that decreased from 0.59 +/- 0.04 to 0.44 +/- 0.02 at 900 degrees C. It was importantly found that the tribological properties improved, but the mechanical properties declined slowly, especially when the h-BN content increased from 20 to 30 vol%. The surface brittle fracture was considered to be the main wear mode at 900 degrees C, especially for the composites with 50 and 70 vol% h-BN.