Study of consolidation features for fragmentally nanostructured hard metal composites

The results of experimental studies combined with modeling and prediction methods for the properties of hard metal composites show that modification with additives of ceramic nanoparticles and composite powders (WC-Co) allows to control microstructure parameters and provides the increase in binding durability and the level of physicomechanical properties of a hard alloy in general. Simultaneous complex application of submicrocrystalline WC carbides coated with Co layer and alloying additives of Al2O3 nanoparticles - grain growth inhibitors of the main phase, can be consid- ered as the most perspective direction of nanostructured hard metal with increased hardness, strength and crack resis- tance production. The coating of carbide particles with a binder layer is an effective starting method that allows to ob- tain a volumetric billet with maintaining the unique properties of the initial nanopowders and ensures a uniform distri- bution of the phases (WC, Co, Al2O3). Such a multiphase fragmented nanostructured composite is characterized by additional heterogeneity, determined by differences in size and elastic phases properties. By combining the sizes and properties of the phase components in such a heterogeneous composite, it is possible to provide an increase in the frac- ture energy, i. e., Palmkvist crack resistance up to 16-18 MPa m1/2 (due to inhibition on nanoparticles inclusions, stress reliefs and changes in intercrystalline crack trajectory, its length decrease). Based on the proposed stereological mod- els and the experimentally established relationships between composition and microstructure parameters, the required volume concentrations of nanoparticles additives and composite powders (WC-Co) were determined.