Advanced Materials Research Vol. 1040

Abstract: The tribotechnical properties of ultra-high molecular weight polyethylene (UHMWPE) based composite filled with hydroxyapatite (HA) microparticles under dry sliding and lubrication of distilled water and plasma blood wear investigated with block-on-ring. It was shown that modification of UHMWPE by HA microparticles of 20 wt.% results in decrease of wear intensity at dry sliding up to 4 times. The under lubrication, wear intensity of pure UHMWPE and microcomposite are deceased up to 50–70% as compared with under dry sliding. Permolecular structure of pure UHMWPE and microcomposite are spherulitic structure and the HA microparticles were dispersed in the UHMWPE matrix.

Abstract: The present paper is devoted to the study of the kinetics of luminescence flash in LiF-WO₄ crystals and development of the model to describe the kinetics of cathodoluminescence growth under pulsed excitation.

Abstract: In this research it was examined the influence of crystallisation conditions binary leaded bronze on parametres of a received microstructure. Change of crystallisation conditions was carried out by change of cooling melt speed, through preliminary heating of casting moulds. Quantitative regularities of influence of cooling rate of explored bronze on parametres dendritic cells, grain size are presented. The data about formation of lead inclusions between dendrites of a copper matrix are published as well. It is shown that high rates of cooling of an order 100-150°С/c lead to dendritic structures formation containing only axes of the first and second order. Decrease of cooling rate at the moment of crystallisation to the values less 15°C/c leads to appearance and growth of axes of 3rd order at dendrites matrix.

Abstract: Using the scanning electron microscopy data the main regularities of the fatigue crack propagation in the 17Mn1Si steel were studied. Based on fracture surface observation and analysis one can testify that the transition of the leading role of deformation and failure from the lower structural level to the higher one has the ordered pattern.

Abstract: The article considers the technology for producing GX120Mn13 steel with high manganese content altered by a special modifier in order to improve the constructional durability of the manufactured parts. The ultra-dispersed powder of refractory metal oxides is used for the modification process. The samples are produced in the series of casting and tested mechanically. The structural research demonstrates the improvement of the steel microstructure and its mechanical characteristics. It has also revealed that the size of an austenite grain and nonmetallic inclusions on grain boundaries are reduced, and sulphide inclusions are partially dissolved, which has a positive impact on the operation characteristics of the steel.

Abstract: The paper presents experimental results on influence of tungsten, molybdenum nanopowders and aluminum oxyhydroxide phase introduced into the molten pool on the corrosion resistance of welded joints. It was shown that the nature of nanopowders significantly impacts intercrystalline corrosion of the welding joint.

Abstract: The article focuses on the investigation of the properties of alumina-zirconia ceramics possessing high mechanical characteristics and good conductivity at high temperatures. Measurement results of the dielectric dissipation factor, dielectric constant, electric conductivity when using direct and alternating current for the ceramics samples of 80%(ZrO₂-3%Y₂O₃)-20% Al₂O₃ composition are presented in the paper. Measurements were conducted simultaneously in the electrostatic field in vacuum while heating the samples to the temperatures ranging from 300 to 1700K. Investigations showed that alumina-zirconia ceramics at high temperatures obtains ferroelectric properties not typical of these structures.

Abstract: Research using electronic microscope was carried out to study the structural and phase and deflected mode of material of hot-forged billets. It was revealed that the scalar density of dislocations in ferritic grains and in ferritic perlite layers of forging steel which cracked after manufacturing operations is one and a half time higher than in conditions material. Metal in this condition has higher content of sulfide of plate-type morphology. It has established that the reason of unwanted structural and phase condition is high carbon content, which lead to overheat of metal both in plastic working and final heat treatment.

Abstract: Set of polyaromatic sulfonates for tracer analysis of oil field as a result of fluorescent spectra study is recommended. Simultaneous determination of fluorescent polyaromatic sulfonates is confirmed by the applicability and reproducibility of the fluorescent method.

Abstract: A simple green method for the hydrodediazoniation of arenediazoniumtosylates in water solutions in the presence of Fe-core/carbon-shell nanoparticles as a reagent was developed. In this course, nanoparticles were used as a hydrogen source, but not water.