Sensitivity of a vibroacoustic signal to a change in the state of the surface layer of ceramics during frictio

The high information content of the vibroacoustic signal in the frequency range of 10‒16 kHz to the change in the state of the surface layer of the ceramic sample during frictional interaction with the steel disk was established. The results obtained indicate the possibility of using vibration diagnostics systems for monitoring the state of ceramic parts during operation and fi tests.

The correlation of the vibroacoustic signal with the wear of a ceramic part during frictional interaction with a steel disc

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High-temperature friction units with carbon-containing materials

The frictional interaction of carbon-carbon composites with steel at high temperatures is considered. Antifriction properties of carbon composites are investigated at friction on a steel at speeds of 0,050,25 m/s and pressures of 0,31,0 MPa. The advantages of Hardcarb-T material in comparison with Argalon-2D material are experimentally determined. Keywords: temperature, friction, contact pressure, composites, steel, speed, friction coefficient. [email protected]

Research of the frictional interaction of a powder coating and a metal counterbody during sliding friction

Methods of metallographic analysis and profilometry are used to study the friction surfaces of wear-resistant coatings with CоAl2O4 and CuAl2O4 modifying additives of ultradispersed spinels during sliding friction with counterbodies made of VK6 hard alloy and St6 steel. To describe the frictional interaction of a powder coating with a metal counterbody during steady-state wear, a statistical model is developed based on the binomial distribution of removed particles. Keywords: coating, counterbody, sliding friction, frictional interaction, wear, statistical modeling, binomial distribution. [email protected]

Investigation of the formation of friction surface microgeometry of a wear-resistant coating during friction with a metal counterbody

Were is researched the friction surfaces of wear-resistant coatings with modifying additives Al2O3 and metal counterbody made of ShH15 steel, and also reveals the factors that influence the formation of coating microgeometry of surface during sliding friction. A statistical model has been developed based on the binomial distribution of removed wear particles to describe the frictional interaction during friction of the coating with a metal counterbody.

Features of structural adaptability of polymer composite coatings

Coatings based on thermosetting and thermoplastic polymer binders using mechanically activated silicate fillers from local natural raw materials (from Koytash deposit), activated on a mechano-activator of wollastonite of different dispersion were investigated. The studies conducted made it possible to establish the effect of the surface roughness of the material on the cotton fiber damageability under their frictional interaction and the phenomena occurring in the polymer-cotton tribosystem, where, after the end of non-stationary friction, i.e. during the running-in period with a stable frictional interaction, the processes of formation of dynamic tribostructures continuously occur. These tribostructures provide a certain stable and minimum value of the friction force, and their destruction is compensated by their restoration, owing to information feedback.

Improving the Quality of Running-in of Car Engine Parts During Running-in Using a Complex Action Additive

The purpose of the work is to improve the quality of the process of running-in of car engine parts during running-in using the additive of complex action. The tasks are the theoretical substantiation of the formation of transfer films during engine running-in and the conduct of comparative studies of the developed complex additive to M-8-B motor oil. The paper substantiates that in order to improve the quality and accelerate the running-in of car engine parts during running-in, a complex additive is required, which includes both surfactants and chemically active substances. The preconditions for obtaining transfer films on the friction surfaces of engine connections during running-in are considered. A frictional interaction is described in the case when the soft transfer film is strong and fixed on the main material, and the sliding surface coincides with the boundary between the film and the counter body. The presence in the zone of contact of surfactants with metals leads to the implementation of a special mechanism of frictional interaction, characterized by a colloidal system of particles in the lubricant and structural transformation on the interface. Comparative laboratory studies of the proposed additive were performed. The dependence of the moment of friction force on the time of the tests, the surface roughness of the samples worked in different compositions, as well as the distribution of the microhardness of the samples by depth were investigated. Based on the analysis of additives for running-in of engine parts, the use of complex additives containing surfactants and chemically active substances is determined as promising. Based on these studies, an additive containing ferrite spinel has been proposed. This allows you to control the running-in process through the structurally sensitive properties of the spinel composition. The use of the proposed additive of complex action helps to change the structure of the surface layer of the metal during friction under the action of temperature and load, which leads to improved quality of running-in of car engine parts during running-in.

A machine for real-time estimation of the tribological characteristics of materials

A reciprocating friction machine Tribal-T intended for automated quality control of the rubbing surfaces of tribopairs is described. The distinctive feature of the machine consists in implementation of the forced relative motion due to the frictional interaction of the rubbing surfaces fixed on the drive and conjugate platforms. Continuous processing of the signals from displacement sensors is carried out under conditions of continuous recording of mutual displacements of loaded tribopairs using classical approaches of the theory of automatic control to identify the tribological characteristics. The machine provides consistent visual real time monitoring of the parameters. The MATLAB based computer technologies are actively used in data processing. The calculated tribological characteristics of materials, i.e., the dynamic friction coefficient, damping coefficient and measure of the surface roughness, are presented. The tests revealed that a Tribal-T reciprocating friction machine is effective for real-time study of the aforementioned tribological characteristics of materials and can be used for monitoring of the condition of tribo-nodes of machines and mechanisms.