CRACK RESISTANCE OF PCBN COMPOSITES DETERMINED BY THE VICKERS PYRAMID INDENTATION METHOD

Abstract

The crack resistance of PCBN composites of the BL group with a volume fraction of cBN in the structure of 45, 50, and 65% and the BH group with a volume fraction of cBN in the structure of 83 and 86 % was determined by the Vickers pyramid indentation method with a load of 30 kg on the indenter. The Young's modulus values for the studied PCBN composites were determined (calculated). It was shown that median cracks form in the BL group composites during indentation, and Palmqvist cracks form in the BL group composites. The limit values of crack resistance for PCBN composites of the BL group were determined depending on their hardness and elastic modulus. For all measurements, statistical data processing was performed with the determination of confidence intervals at a confidence probability of 70%.