scholarly journals Theoretical justification of the influence of change of dilaton and compression bonds of atoms of materials of machine parts on their tribological effect

2021 ◽  
Vol 100 (2) ◽  
pp. 71-78
Author(s):  
V. Aulin ◽  
◽  
S. Lysenko ◽  
A. Hrinkiv ◽  
О. Derkach ◽  
...  

The course of friction and wear processes in the surface layers of conjugations of machine parts is clarified on the basis of the idea of dilaton and compression bonds of atoms in the materials of parts. Dilaton-compression connections are random in nature, and therefore in this work the theory of destruction of parts by S.M. Zhurkov, thermodynamic and quantum physical approaches. The entropy at the macro-, meso- and microscopic levels and the local regions of the materials of conjugation of the parts subject to friction loading are considered. In the diagram of the state of atomic-molecular bonds the dependence curve Fi(ri) or Ti(ri) is considered and the analysis of transformations of bonds according to the specified diagram is carried out. From the point of view of solid state physics and tribophysics, the manifestation, evolution and consequences of the influence on the characteristics and properties of the friction zone of dilaton and compression bonds of material atoms are considered. Composite materials (composite coatings) are substantiated in more detail. This takes into account the assessment of the concept of material stresses in the friction zone, the ability to relax it, as well as the presence of the SD effect. The fracture process is associated with the modulus of elasticity of the components of the composite material and the bulk content of the filler. An appropriate condition is proposed, which determines the tribological efficiency of composite materials and coatings.

Author(s):  
Viktor Aulin ◽  
◽  
Ivan Vasylenko ◽  
Mykhailo Krasota ◽  
◽  
...  

A number of parts of car systems and units in the process of operation are subject to intensive wear and fatigue processes, and therefore do not withstand the planned service life. An important reserve for increasing the reliability and efficiency of such equipment is the strengthening of the working surfaces of its parts with composite materials and coatings. This method of strengthening makes it possible, controlling the structure of composite materials and coatings, to form the necessary set of performance properties of parts to ensure the appropriate level of reliability and increase durability. However, this requires theoretical justification to establish a correspondence between the structure, composition, distribution of chemical elements applied to the parts of the composite coating and their performance properties, such as wear resistance, fatigue strength, etc. The purpose of this work is a theoretical justification for the use of the method of cluster components to determine and form a set of necessary performance properties that ensure reliable and efficient operation of parts of systems and units of cars. The article theoretically substantiates the operational properties of automobile parts hardened with composite coatings using the method of cluster components. By choosing certain sets of parameters, as well as varying the system of restrictions on them, it is possible to form a complex of operational properties of parts. To simplify the packing model for composite materials and coatings, it is assumed that fillers of different compositions have an isometric shape and the same size. A regular structure is proposed, corresponding to the packing of spheres of the same size. It is shown that such packings form lattices similar to atomic crystal structures. The dependences of the function of the properties of composite coatings on the content of each of the types of cluster components are revealed. The method of cluster components, describing changes in the properties of composite coatings from the ratio of components, makes it possible to control a set of operational properties and obtain high-quality coatings to increase the durability of parts of systems and vehicle units. As a result of the conducted researches it is offered to consider composite coverings and composite materials as the systems characterized by a certain complex of operational properties depending on filler content and regularity of structure. According to the theory of cluster components, the content of the component determines the parameters and properties of composite coatings and materials. The method of cluster components makes it possible to present a set of operational properties as an additive model of its components. The packaging of components in composite coatings and materials is represented by atomic crystal structures: simple cubic, volume-centered cubic, face-centered cubic and hexagonal densely packed. The implementation of the method of cluster components on the example of a binary system of components A and B is considered. The basic configuration in accordance with the approximations of the statistical ordering theory is chosen. The visual interpretation and physical content of a mixture of powders, components of composite coatings and materials, particles A and B are given. The configurational entropy and formation of cluster components of the intermediate composition AB along with the basic AA and BB are considered. Based on the π-theorem, a complete set of quasi-chemical reactions is outlined. For binary composite coatings and materials АСВ1-С the matrices of size and relative content of components are constructed, the quasi-chemical formalism of the method of cluster components and the law of active masses for volume-centered cubic lattice are used. This is taken into account when building functional models of operational properties. Their specification on the criterion of correctness is carried out.


Author(s):  
Simona BOICIUC ◽  
◽  
◽  

The undertaken research which is described in this paper aims at the corrosion behaviour of composite coatings in nickel matrix using as dispersed phase technical alumina with dimensions of 5 μm and their characterization from a microstructural point of view. The corrosion resistance in the saline fog of the coatings is influenced by the microstructure, the stresses developed in the layer and the roughness.


2020 ◽  
pp. 339-342
Author(s):  
V.F. Bez’yazychny ◽  
M.V. Timofeev ◽  
R.V. Lyubimov ◽  
E.V. Kiselev

The theoretical justification for the hardening process of the surface layer of machine parts for combined methods of surface hardening with subsequent application of strengthening coatings, as well as reducing or increasing the fatigue limit due to the fretting process is presented.


2020 ◽  
Vol 10 (1) ◽  
pp. 454-461
Author(s):  
Piotr Sęk

AbstractLaser surface texturing is currently the most developed technique for producing fully reproducible microcavities on the surfaces of machine elements. From the point of view of texture technology, an important aspect is the proper selection of process parameters to obtain texture elements with desirable and repetitive geometries and physicochemical properties. Surface texturing improves mottling and fretting resistance and is also used wherever the adhesion properties of surface layers (printing techniques, bonding materials, biological and chemical activity, coatings, etc.) are important. The article shows the possibility of applying statistical functions to the selection of appropriate machining parameters to obtain microgeometry useful in the application of textured surfaces [1].


Wear ◽  
2019 ◽  
Vol 426-427 ◽  
pp. 228-238 ◽  
Author(s):  
Shaojun Qi ◽  
Xiaoying Li ◽  
Hanshan Dong

2010 ◽  
Vol 44 (21) ◽  
pp. 2487-2507 ◽  
Author(s):  
G. Vargas ◽  
F. Mujika

The aim of this work is to compare from an experimental point of view the determination of in-plane shear strength of unidirectional composite materials by means of two off-axis tests: three-point flexure and tensile. In the case of the off-axis three-point flexure test, the condition of small displacements and the condition of lift-off between the specimen and the fixture supports have been taken into account. Some considerations regarding stress and displacement fields are presented. The in-plane shear characterization has been performed on a carbon fiber reinforced unidirectional laminate with several fiber orientation angles: 10°, 20°, 30°, and 45°. Test conditions for both off-axis experimental methods, in order to ensure their applicability, are presented. Off-axis flexure test is considered more suitable than off-axis tensile test for the determination of in-plane shear strength.


2021 ◽  
pp. 36-40
Author(s):  
F.F. Yusubov

Tribotechnical indicators of environmentally friendly frictional composite materials with phenol-formaldehyde matrix are studied. Friction tests were carried out on a MMW-1 vertical tribometer according to the pin-on-disk scheme. Keywords: brake pads, composites, friction and wear, plasticizers, degradation, porosity. [email protected]


2017 ◽  
Vol 63 ◽  
pp. 194-203 ◽  
Author(s):  
Eulalia Gliścińska ◽  
Dominik Sankowski ◽  
Izabella Krucińska ◽  
Jarosław Gocławski ◽  
Marina Michalak ◽  
...  

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