This paper reviews experimental research on nanocomposite protective coatings of various chemical compositions and structure. For adaptive multielement and multilayer systems with specific phase composition, structure, substructure, stress state, and high functional properties, formation conditions are considered; the behavior of such systems under extreme operating conditions and in tribological applications is examined; the structural, phase, and chemical composition are discussed as well as the hardness, friction and wear at elevated temperatures; and the adhesive strength of hierarchical protective coatings is analyzed. Finally, the adaptive behavior under different tribological test conditions of multifunctional, multilayer coatings as a function of their properties and structure is examined.
The results of the investigations into the technological formation of new wear-resistant polymer composites based on polytetrafluoroethylene (PTFE) filled with disperse synthetic and natural compounds are presented. The efficiency of using PTFE composites reinforced with carbon fibers depends on many factors, which influence the significant improvement of physicomechanical characteristics. The results of this research allow stating that interfacial and surface phenomena of the polymer–solid interface and composition play a decisive role in PTFE composites properties. Fillers hinder the relative movement of the PTFE molecules past one another and, in this way, reduce creep or deformation of the parts, reducing the wear rate of parts used in dynamic applications as well as the coefficient of thermal expansion. The necessary structural parameters of such polymer composites are provided by regimes of process equipment.
NUNational Academy Of The National Guard Of Ukraine
National Academy Of The National Guard Of Ukraine
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Risk assessment is an integral part of an enterprise's quality management system. The risk of low quality products is the most significant risk, as it is directly related to the concept of enterprise competitiveness. The paper analyzes the scientific papers related to the assessment of the quality of products, processes and services, their disadvantages, possible limits of application. It is proposed to use mathematical dependences to obtain estimates of product quality indicators on a dimensionless scale. Knowing the density function of random variables of product quality indicators and knowing the mathematical dependence of their estimates on a dimensionless scale, it is proposed to obtain the density function of estimates. Knowing the function of the density of estimates of quality indicators, it is proposed to find the probabilities of risks of the assessment of quality indicators in any given interval on a dimensionless scale. A method for assessing the risks of low quality products has been developed
The main aim of presented article is to present methodology how sophisticated products as compressor equipment can be considered and analysed as a complex technical system which consists of jointly operating components – a set of hardware, software, operational staff and documented information. In process modelling, these components are interacting in different processes of inputs, outputs, mechanisms (resources) or management. Based on the regulatory requirements for each component of the system, a key efficiency indicator can be identified. This allows to control the process and make appropriate decisions to improve the system. The application of the proposed methodology for the development and implementation of an integrated management system reduce the cost of resources and significantly improve the quality of the implementation of processes.
The impact of fillers in the epoxy oligomer on the test culture of the marine ecosystem was investigated. The content of additive—biocides—was selected based on the complex research using STAT-GRAPHICS® Centurion XVI. The ecotoxicity of composite surfaces was determined in model systems using methods which are standard in eco-microbiology. The microorganism was identified by studying morphological, cultural, biochemical, and antigenic properties. Studies of the structure and the microrelief of the surfaces of composite materials were conducted using scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy. Based on comprehensive research, it was established that the composition of oxytetracycline with content of q = 1.5 wt% and nanosilver with a content of q = 0.075 wt% per 100 wt% of the DER-331 oligomer and 10 parts by the mass of the TETA hardener ensures the formation of a porous nano-heterogeneous structure of the coating, which leads to the acceleration of the release of silver ions from the surface of the polymer. The rational content of the complex additives of biocides ensures adhesion to the cell wall of bacteria with subsequent penetration into it and subsequent change to the cell membrane, its death, and, therefore, the suppression of the fouling process of metal structures.