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The development of new methods for obtaining materials with predetermined operational properties that ensure the durability and the wear resistance of friction units is an urgent problem in modern material science. The article considers the effect of ultrasonic pressing modes with simultaneously superimposed low-frequency amplitude modulation on the mechanical and tribotechnical properties of polytetrafluoroethylene. The comparison of the obtained research results of the new technology is carried out with the traditional pressing technology. The results of studies indicated that the technology of ultrasonic pressing with the simultaneous application of low-frequency amplitude modulation makes it possible to increase the mechanical properties of PTFE: the tensile strength by 15 %, elongation by 13 %, the elastic modulus by 8 %, the hardness by 12 %, while the intensity of the mass wear rate is reduced by 40 %, and the coefficient of friction by 27 %. [ABSTRACT FROM AUTHOR]

The article describes the influence of ultrasonic vibrations energy on the submolecular structure and tribotechnical properties of polymer composite materials based on polytetrafluoroethylene. Comparative analysis of the performed experiments showed that the introduction of ultrasonic vibration energy during pressing effects an increase in the wear resistance of polymer composite materials while maintaining low values of the coefficient of friction. In the friction process the submolecular structure changes because of a significant decrease in the size of crystallite blocks due to their fragmentation. [ABSTRACT FROM AUTHOR]

The article considers way to increase the microhardness of the surface of tungstenless hard alloy based on titanium carbide with a binding phase of intermetallic titanium nickelide (TiNi). The matrix in solid composite materials must exhibit the capability to arbitrary form making during the deformation process of the composite and to strengthen its positions and good wet particulate, providing a strong bond along the phase boundaries and high density during sintering. The increase of strength properties and hardness of composite materials are achieved by improving the microstructure, repairing defects in their structure, while improving the wetting processes with the binder phase. It was established experimentally that the process of irradiating the surface of polished samples the ions Ar+ and Zr+ with energy about 20 keV and a dose of 1017 ions/cm² of a solid alloy leads to a significant change in the microhardness of the material. It happens due to the formation of quenching point defects occuring during intense heating and cooling of composite samples. Structure formation occurs in extremely non-equilibrium conditions of interaction of the surface of tungstenless alloy with a concentrated energy flow, during the implantation the samples of solid alloys. The data are presented, visually showing that increasing the strength and microhardness is promising way to increase the wear resistance of products intended for earth works related to drilling wells and laying tunnels. [ABSTRACT FROM AUTHOR]

In this paper, the causes of the drop in the mechanical properties in the process of manufacturing the “bend-out” part are investigated. On the basis of the obtained results, non-standard heat treatment is proposed, allowing to increase the mechanical characteristics to the initial values. Experimental data showing the validity of the proposed heat treatment regimes are given. [ABSTRACT FROM AUTHOR]