Melnik O. Composite high-strength, wear-resistant materials with multifunctional purpose based on ZrO2 nanopowders

Research object: electroconsolidation processes nanopowder mixtures based on partially stabilized zirconia with additions of Al2O3 and WC. Research purpose: development of technological foundations of the method of hot pressing with direct transmission of high-ampere electric current (electroconsolidation) composite materials with high mechanical properties (hardness, strength, fracture toughness) based on zirconia nanopowders with additions of alumina and tungsten carbide. Research methods and equipment: X-ray diffraction, chemical analysis, electron-microscopic (scanning and atomic force microscopy), complex of physico-chemical methods and statistical methods of computerized experimental design. Technical properties of developed materials have been determined in accordance with standard techniques. Theoretical and practical results: effective regimes of obtain the composite materials based on nano-sized zirconia by hot pressing with direct transmission of high-ampere electric current have been developed from the scientific principles and the experimental data; the criteria of the optimal content of nanoscale additives Al2O3 and WC in materials relative to achieve the specified strength characteristics; technological rules for manufacture abrasion resistant ceramic products for the working part of the waterjet nozzle (focusing tube) have been developed.Novelty: scientific novelty of the work lies in the development of the theoretical foundations of technology electroconsolidation nanopowders systems ZrO2 - Al2O3 and ZrO2 - WC on the basis of theoretical and experimental studies of regularities of structure formation using powders of different morphology and properties of dense composite materials, thus improving their abrasion resistance and strength characteristics. Degree of implementation: results of the work have been implemented in the academic process of Ukrainian State Academy of Railway transport (UkrSART). Sphere of use: results of the work may be used at manufacturing of technical ceramics and articles made of composite materials with high strength, wear and corrosion resistance and on the mechanical engineering industry enterprises. Scientific results may also be used in higher education institutions for training production engineer and material engineer.