. This article on the basis of experimental studies shows the data about γ-quanta affecting VK8 alloy. With structural studies it is found that γ-quanta irradiation leads to the volume fraction of the ternary phase and a decrease in the concentration of defects in cobalt. The irradiation γ-quanta irradiation leads to an increase in the content of the ternary compound type η-phase (CoxWyC) of variable composition and decrease the concentration of defects in the cobalt matrix. Formation of the ternary compound by irradiation determines the mechanical properties of the alloy, because the appearance η-phase results in an alloy with a grain size of less hardness alloys.