The process for obtaining PCBN composites by the reaction sintering powders cBN with Al at pressures of 7.7 and 4.2 GPa with a preliminary dispersion of Al in the mixture at p = 2.5 GPa and T = 1300 K is designed in the ISM NASU. The problems of sintering nanopowders cBN are following: high cohesive activity, tendency to a phase transition cBN→hBN; difficulty infiltration due to the small size of the pores. cBN submicron powder advisable used in the mixture cBN-Al, in submicron cBNthe 15 % nanofraction located on the surface of larger particles. Nanosized particles before others interacted with Al. The reaction product AlN inherit the size and morphology of nanoparticles cBN. Instead of a continuous frame cBN, resulting in sintering micron, highly dispersed structure of phase cBN in the shell with AlN nanoscale grains (15-30 nm) is formed. The material has a high fracture toughness - 10.5 MPa∙m^1/2 at a hardness 27 GPa.

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