Simulation of equilibrium configurations and mechanical properties of tungsten carbide nanoparticles and nanoscale cobalt layers was fulfilled using the density functional and pseudopotential methods as an application to hard alloys constructed by the powder metallurgy technology. It has been found that small particles (less than 15 WC atomic pairs) have cubic structures like NaCl; bigger particles are characterized by trigonal symmetry but their internal atomic structure keeps a NaCl-like type of ordering for W and C atoms. It has been shown that Young modulus for nanoparticles is several times as high as Young module for bulk. The tensile strength for nanoparticles is also predicted to be significantly larger than for bulk materials. Vacancies decrease the tensile strength; however, Co atoms can incorporate into vacancy positions and restore the tensile strength approximately to a faultless case. It is shown that when the cobalt interlayer between WC crystallites is reduced to a nanoscale thickness, its cross-section tensile strength increases twice but the shift module decreases six times. The hardness of such layers can be 3-4 times as high as that of bulk cobalt.
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