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Vol 37, No 6 (2016)
- Year: 2016
- Articles: 8
- URL: https://ogarev-online.ru/1068-3666/issue/view/14119
Article
Tribology: Trends in the half-century development
Abstract
The paper treats in brief trends in development of tribology (a concept formulated by Peter Jost) in the half-centennial period, setting a stress on the research history of friction, lubrication and wear processes along with their role in engineering and social life. Actuality of the new tribological trends is stated in economy of energy and materials, intensified usage of friction joints in modern engineering, including aerospace, biology, medicine and ecology. The scale factor significance in tribology and nanotechologies is underlined.
513-516
Calculation of friction for indenter with fractal roughness that slides against a viscoelastic foundation: Improved model
Abstract
Additional results on calculating the deformation force of friction for a rough indenter sliding on a viscoelastic foundation are presented. The results consider the influence of the roughness on the normal contact load. As in earlier studies, the deformation properties of a foundation are described by the Kelvin model and the roughness of an indenter is represented by the Cantor–Borodich fractal, which consists of a set of rectangular asperities.
517-518
Ion beam processing of austenite steels: Tribotechnical and corrosion properties
Abstract
This article presents data on wear and corrosion resistance of 10Kh17N13M2T and 55Kh20G9AN4 austenite steels processed by nitrogen ions. It has been demonstrated that the temperature of ion beam nitrogenation significantly influences structure and phase transformations and properties of materials. The obtained values of electron work function agree with the data of tribotechnical and corrosion tests.
519-522
Increase in the coefficient of friction of the rolling stock disc brake via fluid cooling of its friction elements
Abstract
The paper presents the results of theoretical and experimental investigations in the effect of a partial heat energy removal in the friction contact zone upon the disc brake coefficient of friction during braking. A fluid cooling system for the disc brake friction elements has been proposed based on a recuperative liquidpneumatic heat-exchange apparatus.
523-528
Studying the properties and structure of polytetrafluoroethylene filled with Belum modified carbon fibers
Abstract
The effect of Belum discrete carbon fibers on the service properties and structure of polytetrafluoroethylene has been studied. It has been shown that a filling of polytetrafluoroethylene with 1–5 wt % of carbon fibers does not worsen the stress–strain properties of composites. The introduction of carbon fibers improves the tribological characteristics of polytetrafluoroethylene. The thermodynamic and structural studied of polymer composites have been performed.
529-534
Study on tribological properties of the DV–FV polyarylate system
Abstract
Tribological properties of two fully compatible polyarylates having similar chemical structures and different kinetic chain flexibilities have been studied. During the processing and forming the polyarylates, a polymer mixture system containing the copolymer has been formed. It is shown that the formation of the DV‒FV polymer system by mixing the “flexible” and “rigid” polyarylates leads to a sharp increase in the glass transition temperature and to a more complicated mechanism of friction characterized by a specific structure of the transfer products. It leads to the formation of metal-polymer system on the counterbody surface. This works provides the possibility to control the tribological properties of polymer mixtures.
535-543
Biotribological properties of dentures lubricated with artificial saliva
Abstract
This paper presents the results of tests on the effect of adsorbed films of saliva substitutes on the tribological characteristics of metal alloys based on the example of stainless steel 316LVM and two alloys, Co–Cr–Mo and Ti‒6Al–4V. Saliva substitutes were prepared based on animal mucin and xanthan gum dissolved in phosphate buffered saline (PBS). The adsorbed salivary films significantly reduced the coefficient of friction of the tested biomaterials. Low values of coefficient of friction have been achieved during the tests using PBS + mucin. The analysis of wear of tested materials showed lowest values in the process of friction using PBS + mucin + xanthan gum. An IR analysis of the studied surfaces confirmed the presence of wear marks on the adsorbed salivary films.
544-551
Effect of fatty-acid composition and structure of alkyl radicals of plant oil triglycerides on their tribotechnical characteristics
Abstract
Sunflower, corn, rapeseed, olive, and linseed oils have been tested on a four-ball friction machine. The fatty-acid composition of oils has been determined. It has been shown that the similarity of their antiwear characteristics and the holding range of surface-active substances is related to the equivalence of the chain lengths of alkyl radicals. It has been determined that the activation of unsaturated bonds as a result of the oxidation and thermomechanical exposure upon friction has a positive influence on the friction interaction due to tribopolymerization and film formation on the abrasive surfaces. It has been stated that, with change in the average chain length of alkyl radicals and the number of unsaturated bonds by the addition of corresponding triglycerides, one can control the tribotechnical characteristics of plant oils.
552-555