INVESTIGATION OF STRUCTURE FORMATION FEATURES AND PROPERTIES OF COPPER-BASED POWDER PSEUDOALLOYS MODIFIED BY ZnO AND TiN NANOPARTICLE ADDITIVES

The multi-method investigation of Cu–ZnO (nano), Cu–TiN (nano) copper-based materials using standard mechanical testing methods along with metallographic, electron-microscopic research using energy-dispersive and thermal analysis allowed to identify stable correlative relationships between the content of nanoparticle additives, microstructure parameters and mechanical-and-physical properties of pseudoalloys. Processing technologies are suggested and justified to improve the uniform distribution of ZnO and TiN modifying nanoparticle additives over the pseudoalloy volume eliminating their conglomeration. The paper proposes novel original methods of nanoparticle introduction to the matrix material as master alloys of Cu–Al–ZnO or copper powders coated with TiN nanoparticles. High surface area and reactive capacity of nanopowders provides for reduced ceramic phase in electrocontact materials (down to 2,0–3,0 % instead of 10–15 % compared with known commercial ones). In this way, general properties typical for matrix materials (copper), i.e. heat and conductivity, remain significantly high, and at the same time, the general level of mechanical-and-physical properties of composite pseudoalloys such as hardness, strength and wear resistance as well as their operational properties is increased. Main properties of copper-based composites include resistivity (ρ ~ 0,025 μΩ·m), strength of bonding to Тугоплавкие, керамические и композиционные материалы 20 Известия вузов. Порошковая металлургия и функциональные покрытия  4  2017 the contact support material (σ ~ 2 MPa), dispersed ceramic phase inclusions that reduce electroerosive wear (2,5 times) in comparison with conventional materials.