International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The paper presents the results of studies of tribological properties of the contact of the tool steel composition Fe-18W-4Cr-1,2V with the magnesium alloy AZ91D strengthened by submicron powder filling out of SiC and severe plastic deformation (SPD), namely equalchannel angular pressing (ECAP). It is stated that introduction of SiC powder filling to the magnesium alloy the friction coefficient on the moving frictional contact increases, the wear rate reduces. These tribotecnical characteristics are influenced by the size and volume of the particles of powder filling, normal loading force and slip rate. SPD of the initial material results in reduction of the adhesion constituent of the friction coefficient.

In this paper, we present the results of the tribological studies of commercially pure copper (99.9% Cu) and a low-alloyed chromium bronze (Cu-0.5%Cr), contacting a graphite-containing material. The samples under study were produced with two types of microstructures: a coarse-grained (CG) one, having an average grain size of 100-130 μm after annealing, and a submicrocrystalline (SMC) one, having an average grain size of 0.30-0.50 μm after multi-cycle severe plastic deformation (SPD) processing via equal-channel anglar pressing (ECAP) combined with Conform. It is shown that for the samples produced by ECAP-Conform, having an SMC structure, the friction coefficients are 12 – 20% lower than for the as-annealed samples, having a CG structure.

The paper presents experimental data on the tribological properties of commercially pure titanium with different microstructures with and without coating. As a result of the conducted experiments, it was established that the integral value of the friction coefficient, as well as its adhesion component, are structurally sensitive parameters. It is noted that the ultrafine-grained structure, obtained as a result of intense plastic deformation, contributes to the reduction of the coefficient of friction, as well as to the increase of the load-bearing capacity of tribo-conjugation.

This paper presents the results of preliminary corrosion tests of samples from commercially pure titanium Grade 4 with a coarse- grained (annealed) and ultrafine-grained structure after severe plastic deformation, as well as of samples processed by microarc oxidation and with an ion-plasma coating. The effect of microstructure on the corrosion of the material under study is shown. A comparative evaluation of the corrosion rate is performed.

The conditions are substantiated for the loss of thermodynamic stability of a tribosystem and for its adaptation with a decreasing wear rate at the moving frictional contact of parts from materials with an ultrafine-grained structure produced by equal-channel angular pressing. The regularities of the influence of the structure’s dispersion degree and the friction contact’s temperature on the tribotechnical characteristics of ultrafine-grained materials are established theoretically and experimentally.

This work presented the results of tribological studies of commercially pure copper (Cu 99.9%) and low-alloyed chrome bronze Cu-1%Cr in contact with a graphitiferous plate EK-40. Samples from copper and copper alloy were prepared to obtain two kinds of grain size of microstructure. Two schemes were used for tribological studies. The first scheme was used during reciprocal movement to evaluate the friction coefficient. The second scheme was employed to evaluate the shear strength of adhesive bonds and the adhesive component of the friction coefficient.Besides, the fulfilled studies determined that the tribological properties of materials depended on the grain size of microstructure. It is shown that an ECAP–Conformed specimen with UFG exhibits 20-30% lower friction coefficients than that of annealed specimen with CG structure. The tribological test results showed that the coefficient of friction decreased, with the decreasing grain size. Therefore, were conclude the coefficient of friction of proposed materials is microstructure-sensitive.

This paper reports on the results of corrosion tests, using alternative methods, of Grade 4 CP Ti samples with coarse-grained (annealed) and ultrafine-grained structures after severe plastic deformation processing. The effect of microstructure on the corrosion of the material under study is demonstrated. It is revealed that the material with a UFG structure has a higher corrosion resistance, as compared to the samples with a CG structure.

This paper reports on the results of corrosion tests, using alternative methods, of Grade 4 CP Ti samples with coarse-grained (annealed) and ultrafine-grained structures after severe plastic deformation processing. The effect of microstructure on the corrosion of the material under study is demonstrated. It is revealed that the material with a UFG structure has a higher corrosion resistance, as compared to the samples with a CG structure.

With the use of computer modeling in the environment of the DEFORM-3D software, a virtual full factorial experiment has been conducted for the processing of commercially pure titanium by equal-channel angular pressing (ECAP) via the Conform scheme. In the course of the modeling, the effect of independent parameters (the rotation velocity of the working wheel, the friction factor on the lateral surfaces of the working wheel and the friction factor between the billet and the die) has been evaluated. As a result of the experiment, a regression equation has been obtained and the most important individual factors and their mutual combinations that influence the response parameter (strain intensity) have been identified.