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The paper presents the results of studies of composite materials based on epoxy resins with different types of filling are considered. It is shown that a material with a metal filler has higher mechanical characteristics compared to a material filled with ceramics. The material retains high mechanical properties at low temperatures and after interaction with petroleum products. Hydraulic tests showed that the material with a ceramic filler withstood only on non-through defects. The metal-filled material has passed the tests for non-through defects and through defects at pressures up to 4,0 MPa. The material with a filler based on Fe and Cr powder can be used in pipeline construction for temporary repair of valves with non-through defects or through defects of valves operating up to 1,6 MPa.

When mining hard coal the underground method is prevailed. This method provides a higher quality of the mineral. Methane emissions occur in coal mines during the development of gasbearing seams. These emissions are the reason for the formation of an explosive mixture when mixed with mine air, and also contribute to the spontaneous combustion of coal. Methane alarms are used to monitor the mine atmosphere. Thermocatalytic sensor is the main element of such a gas analyzer. The sensor is placed in a breathable housing. This body is called a flame arrester. This article discusses the possibility of replacing the material used for the manufacture of a flame arrester. The basis of the existing material is nickel powder. It is proposed to replace it with a cermet bond. The composition of the ceramic material of the part is developed by the author and presented in the article. Replacement of material will lead to a significant reduction in the cost of the part and simplification of the manufacturing technology.

The influence of modification of heat-resistant nickel-based alloys on the crystallization kinetics of alloys was established by the methods of thermal analysis. This effect is expressed in the increase in solidus temperature and, as a consequence, narrowing the crystallization range of the alloy, the increase in the growth rate of a solid solution, and change in the temperature of precipitation of eutectic and strengthening phases. As a result, the use of modification with refractory particles makes it possible to exert an additional effect on the structure and properties of nickel-based alloys without additional heat treatment.

Аs a result of the study, a three-dimensional finite element model of a wheelset with rail sections is developed using a finite element of the ten-node tetrahedron type, and the maximum tangent stresses and maximum equivalent stresses are determined according to the theory of Mises and Dang Wang. It is shown that the maximum shear stresses are observed at a point located at a depth of 4,5–5,3 mm below the surface of the wheel. In case of emergency (short) braking, the maximum stresses take place on the surface of the wheel. With prolonged braking (the movement of the train on a long descent), maximum stresses occur at the point of transition from the disk to the rim on the inside of the wheel, and the value of these stresses is 2,5 times higher than in emergency braking mode. The finite element method is used to determine the stress-strain state of the wheelset of a freight car during braking.

The article presents the results of work on the study of the use of a single-phase rectifier with an additional unit for obtaining pulsed modes for manual arc welding with thin-walled construction by a stick electrode. The proposed scheme of an additional block allows by selecting the parameters of the welding mode to ensure a stable quasistationary process of melting and transfer of the electrode metal. Thus, it becomes possible to weld thin-sheet structures without reducing the diameter of the coated electrode.