Zozulya E. Structure, conductive and mechanical properties of copper based vacuum film composites strengthened by nanodispersed Al2O3

This dissertation is devoted to the creation of a new generation of conductive composites by the method of electron-beam evaporation and simultaneous deposition (condensation) of components from the vapor phase in a vacuum. The results of the study of the regularities and formation mechanisms of the structure of a copper composite with nanodispersed alumina are presented, along with the results of studies of its mechanical properties and electrical resistivity. Structural stability with low contents of oxide under the influence of temperature was been also investigated. The control mechanisms for the formation of nanodispersed oxide particles are established. A model is proposed of three structural zones that differ in the rates of growth of the hardening contribution at the yield point due to grain boundaries, twin lamellas and particles. The stage behaviour during deformation and hardening of composites at room temperatures is investigated, the key role and contribution of the identified steady-state stage of deformation to plasticity is established. The regularities of the effect of the structure of the composite on the electrical resistivity are established, taking into account the scattering of electrons by nanodispersed oxide particles. The concept of a choice of compositions and technological parameters for conductive composites is presented. Based on this concept, the new oxide dispersion-strengthened and modulated (by periodic, layer-by-layer introduction of oxide during the continuous copper condensation) composites with high electrical conductivity, strength and plasticity have been created.