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The paper examines the effect of nanoscale fillers of modifiers of various chemical nature, which are part of a polymer composite material (PCM), on the characteristics of physical and mechanical properties. Carbon nanotubes, carbon black, a product of processing of hydrocarbon raw materials and silicon dioxide were presented as the considered nanoscale fillers. The method of synthesis and testing of composite materials based on polytetrafluoroethylene is presented. According to the results of the study, the influence of nanoscale mono-fillers-modifiers on the physical and mechanical characteristics of antifriction nanocomposites based on polytetrafluoroethylene (PTFE) was determined. The analysis of the test results was carried out and the components of a complex filler for creating a tribotechnical antifriction PCM with high physical and mechanical characteristics were determined. The influence of the concentration of carbon nanotubes in a polymer matrix on the reduction of the characteristics of the physical and mechanical properties of PTFE-based PCM is considered. Micrographs of the PCM structure with inhomogeneities and unstructured sections of the polymer matrix, as well as CNT (carbon nanotube) agglomeration sites, are shown. It is established that complex nanoscale fillers-modifiers with different chemical nature have a significant effect on the characteristics of the physical and mechanical properties of a polymer nanocomposite based on PTFE. A decrease in the relative elongation of the developed PCM with a complex filler modifier based on Aerosil R–106 and carbon black of the N-220 brand was noted, compared with the PCM with mono modifiers. [ABSTRACT FROM AUTHOR]

The relevance of studying the microbial factor in assessing the corrosion activity of the soil near the oil pipeline is confirmed by a number of studies by the authors. The existence of microbial populations in the form of biofilms colonizing the soil substrates of the pipeline represents a certain strategy for their survival in an unfavorable medium. The purpose of the study was to analyze the features of a biofilm formation by micromycetes of the pipeline soil ecosystem during scanning electron microscopy. At the first stage, to study the biocorrosive activity of soil samples, we determined the quantitative content of thionic and sulfate-reducing bacteria, the total concentration of sulfur, iron, and the value of the electrical resistivity of the soil of the underground pipeline. The criterion of biocorrosive activity of the soil was established, which determines the total effect of various corrosion factors. At the second stage, we carried out a mycological study and obtained a micromycetes culture. At the third stage of the research, in its experimental part, the biofilm on the surface of steel samples was studied using electron microscopy as well as qualitative and quantitative elemental chemical analysis. The results of the soil biocorrosive activity studies proved the presence of aggressive, moderately aggressive, mildly aggressive, and potentially aggressive soil samples; there were no very aggressive samples. During the bacteriological analysis of the samples, thionic and sulfate-reducing bacteria and cultures of micromycetes of the genera Penicillium and Aspergillus were identified. During electron microscopy, the areas of the developed biofilm of mycobiota and formed microcracks on the surface of the samples were found, qualitative and quantitative elemental analysis was carried out. [ABSTRACT FROM AUTHOR]

In this work, we study the effect of a pulsed ion beam (PIB) of nanosecond duration of the composition (30% H+ and 70% C+) with particle energy E ≈ 250 keV on the change in the morphology, composition, and properties of tungsten-free hard alloys (BTTS) of the "TiC-NiTi" system. The study of changes in the morphology of the surface layers of TFHA under the action of the ion beam was made by scanning electron microscopy and scanning probe microscopy. Using energy-dispersive X-ray spectroscopy, an analysis of the change in the chemical composition of TFHA was carried out. It is shown that the impact of PIB leads to changes in the composition, structure and microrelief of the surface layers of the TFHA, which, in turn, has a significant effect on the change in their properties (hardness and resistance to gas corrosion). [ABSTRACT FROM AUTHOR]

The article presents the results of a study of the effect of a continuous ion beam (Ar++Zr+) with an ion energy E≈20 keV and an irradiation dose D ≈ 5 1017 ion/cm2 on the phase composition, chemical state, microhardness and corrosion resistance of tungsten-free hard alloys of the system " TiC-TiNi". Scanning electron microscopy was used to study the surface morphology of samples of tungsten-free hard alloys subjected to irradiation by an ion beam. It has been experimentally established that ion-beam treatment provides an increase in the microhardness and corrosion resistance of the samples under study. [ABSTRACT FROM AUTHOR]

Cold forming 45 steel flanges requires a reduced hardness structure. In order to reduce the duration of the technological process of heat treatment, it is proposed to replace full annealing with normalization, followed by high tempering. The work investigated the modes (heating temperature and holding time) of high tempering. It was revealed that at temperatures above 500 ° C, partial or complete replacement of lamellar pearlite with granular one is observed. [ABSTRACT FROM AUTHOR]