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The effect of modifying additive (La2О3) on the activity of Ni-Co oxides was studied for the dry reforming of methane (DRM). The catalysts were prepared by impregnation of the granulated diatomite (D) and characterized by SEM, EDX, H2-TPR, XRD, and AES. It is shown that the addition of 1.5 wt.% La2O3 into the Ni-Co/D composition leads to an increase in the activity of the catalyst, providing a methane conversion that is close under thermodynamic equilibrium conditions in the temperature range of 700‒850 °С. The highest activity is achieved at T = 850 °C, the conversion of methane is 96%, and carbon dioxide is 92%. The addition of lanthanum oxide to the Ni-Co/D composition led to an increase in catalyst stability; after testing in the DRM reaction for 360 min, the deactivation coefficient for methane was 3.4%, and for carbon dioxide 2.5%. While significant deactivation is observed for Ni-Co/D, the deactivation coefficient for methane is 19%, and for carbon dioxide 36%. Many characterization results (SEM, H2-TPR, and XRD) confirm that Ni-Co-La/D has abundant surface oxygen and the presence of spinel structures that contribute to the reactivity of CH4 and CO2, which positively affect its activity.

The tribological effect of differently processed silver coatings and frictional materials on the operating efficiency of piezo-electric actuators (PEA) when using different frictional contact materials were investigated. Best results for PEA speed stability and load-bearing capacity range are obtained when silver coating operates with diatomite compound with minium. Grinding of the silver coating surface improves the PEA characteristics by increasing the effective contact area, i.e. continuous operation of PEA was at relatively wide loading range and the rotation speed was higher. The decrease of rotational speed due to higher loading can be compensated by clamping force. At low loading output torque the frictional material with corundum ensures maximum speed; so this material could be used for low loaded high-speed actuators.

With the development of electroplating, composite coatings of CEP, which are deposited from electrolyte suspensions, are increasingly being used. Composite coatings are obtained in those cases when it is envisaged to modify the surface of metal products to give them new properties. Perspective dispersed material can be carbon particles, because of their large specific surface area, high porosity, and subminiature structure. The obtaining of such material is possible from cheap secondary raw materials (car tires, nutshells, sawdust, bamboo). The purpose of this work is to create a CEP-based on copper with a carbon-dispersed phase. For the experiment, we used a carbon material with a particle size 40 nm, obtained by us, by pyrolysis from secondary raw materials (used tires of machines). To study the effect of the dispersed phase on copper electrodeposition, the optimum conditions for obtaining the CEP Cu-C were determined. 68Morphology and coefficients of friction-sliding of coatings of copper and CEP are studied. Incorporating into the base metal matrix, the carbon particles, embedded in the deposit, determine its further growth. The change in the structure of the electrolytic deposit affects its functional properties. The test of the obtained samples showed that the best tribological properties were found in CEP Cu-C, where the concentration of carbon material was 15 g/L. For CEP Cu-C, the friction coefficient (f) decreases three times compared to copper deposit, and wear by 12 times. Probably this is due to the fact that the carbon material performs the function of dry lubrication due to its layered structure.

Polymer composites on the basis of secondary polypropylene and high dispersive powders of minerals wide spread in Georgia (andesite, quartz sand and a slam) were obtained and investigated their some physical-mechanical, thermal and hydrophobic properties. It is shown that the ultimate strength, and thermal stability extremely depend on the filler concentration and at definite significant of the concentration have maximums. For the composites with binary fillers (quartz sand/slam, quartz sand/andesite and slam/andesite) revealed synergistic effect of anomaly increasing of the ultimate strength at definite proportion of fillers. It is established that modification of the mineral fillers with tetraethoxisilane enhances technical characteristics of the composites.

In present work it has been studied the physical-mechanical and tribological properties of the compositional material which was obtained in the PTFE base with chalcopyrite fine dispersed concentrate as fillers. The PTFE-chalcopyrite composites were prepared by powder metallurgy route containing chalcopyrite particles (2.5, 5 and 10 wt %). The tests have been performed in the friction machine under 0.7 MPa load where as a counterpart the gray cast iron was used. From the beginning, the weight wear was measured after passing some velocity steps (0.25–1.25 m/sec). The worn surfaces of the tested composites and the cast iron samples after working as a tribological pair were analyzed using SEM/EDX methods. The obtained results have shown that the incorporation of optimal quantity (~5 wt %) chalcopyrite particles into PTFE matrix drastically (>102 times) improves the wear resistance comparatively to the unfilled PTFE in the 0.25–1.25 m/sec friction velocity range. In the same testing conditions by the analysis of the obtained results it is determined that at the low velocity friction (

Wear particles originating from disc brakes contribute to particulate concentration in the urban atmosphere. In this work novel nanoporous composite-based and conventional brake materials were test ...

The results of investigation of physical-mechanical and tribological properties of polytetrafluorethylene (PTFE), composites filled with small (5-10 wt. %) amounts of nanoceramic and nano metallic powders are presented. BN, B 4 C and Co were used as nanopowder fillers. At compression by 30 MPa pressure they are subjected to 10 mass % filled composites on the base of B 4 C and Co is equal correspondingly to deformation of 3.20 and 2.46 % that 6.5 and 8.5 times exceeds the index of unfilled polymer. Developed composites have 2-4 times better wear-resistance than that of the commercial “Superfluvis” on the base of PTFE. DOI: https://doi.org/10.15544/balttrib.2015.26

Based on the comparative analysis of the experimental values determined for the tribological parameters for the three novel nano-porous composition base and two conventional brake lining materials while friction with the grey cast iron disc, it was shown the considerable high tribological efficiency of the novel nano-porous composition base lining materials in comparison with the conventional (from EU and USA market) brake lining materials. The explanation is given to the action mechanism of nano-porous composition base brake lining material and its tribological efficiency basing on the "triple phase" tribo-pair model.