Ceramic-matrix composites with a low-cBN content and different matrix compositions including B6O and TiC have been sintered in a toroid-type high-pressure apparatus at pressure of 7.7 GPa and temperatures from 1500 to 2000C. The microstructure, phase and elemental compositions of the produced composites have been studied using electron microscopy and XRD analysis. Mechanical properties and the performance of the sintered tool materials when turning hardened cold work tool steel have been studied.