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

The reliability of mechanisms used in satellites, interplanetary probes, and planetary rovers largely depends on choosing the right lubricant. Unlike devices used on Earth, space mechanisms operate in conditions of high vacuum, extreme temperature changes, and intense radiation, without any possibility of performing maintenance. This means that conventional lubricants used on Earth don’t provide the necessary durability or reliability. The article presents an analysis of the main environmental factors affecting the lubrication process and discusses the properties of the most commonly used types of lubricants in space mechanisms. Special attention is given to perfluoropolyether (PFPE) based greases, multiply alkylated cyclopentanes (MAC), and solid lubricants based on molybdenum disulfide and DLC-type coatings.

The article examines the morphology of high-entropy coatings formed using vacuum technologies on low-carbon steel substrates. Studying the morphology of the surface layers of TiAlSi (N ,C ) coatings formed on low-carbon steel substrates using atomic force and optical microscopy methods made it possible to establish the dependence of the morphological parameters of the coatings on the energy parameters and chemical composition of the substrate. The dependence of the morphological parameters of coatings on the conditions for the formation of vacuum layers on low-carbon steel substrates is also shown.

Designing an electrical resistance heater for vacuum furnace is a result of multiple thermo-technical and electro-technical calculations in order to determine the optimal power. The process of heating must also comply with the technological requirements for temperature differences between the inside and the surface of the processed products. Considering the complicated heat transfer in the furnace, there is no complete methodology for determining the heat conditions of the participants in the heat transfer differentiating in time and space. In this paper it is systemized a sequence of applied mathematical and numerical models as well as geometric dependence for deriving the angular coefficients of radiant interchange in the process of determining the temperature of every participant in the heat transfer in order to refining the E. Angelovaprocess of designing an electrical resistance chamber.

The primary role of the space materials science is to ensure the long-term trouble-free operation of materials and elements of equipment in a space environment. The achievements of space materials science are a solid foundation for solving these tasks. In this paper we present the first part of the analysis of some different aspects of the space environment and their effect on the properties of materials (such as high vacuum conditions, own external atmosphere, collisions with particles, solar electromagnetic radiation, solar wind, penetrating corpuscular radiation) which are located or are mounted on the body of the International Space Station. But there are still problems such as the electrification of satellites, the work of materials in the atmosphere of heavy nuclei, the surface potential of the International Space Station, etc., which will be the subject of our next, second part of this study.

When it comes to space vehicles for humans (as the International Space Station), the most important goal is how to achieve safety in the space vehicles, that people should survive their travel to space and return safely, in good health. In this connection, the primary role of the space materials science is to ensure the long-term trouble-free operation of materials and elements of equipment in a space environment. In this paper we present the second part of the brief analysis of some different aspects of the space environment and their effect on the properties of materials which are located or are mounted on the body of the International Space Station.

The main task of the research is to establish the regularities of the formation of a non-detachable compound of thin-walled elements from the Ni-20Cr-6Al-1Ti-1Y2O3 alloy and to determine the functional condition of the influence of soldering modes on the physical-mechanical characteristics of the compound. It has been shown the modeling of temperature fields in ANSYS 18.1. It has been established that the process of vacuum soldering should take place at a temperature of 1350°C for 15-20 min; the strength of the resulting compound is 390-420 MPa when the sample is stretched. The obtained information can be used as a theoretical basis for the development of the manufacturing process of the elements of the spaceship heat-shielding system.

The main task of the research is to establish the regularities of the formation of a non-detachable compound of thin-walled elements from the Ni-20Cr-6Al-1Ti-1Y2O3 alloy and to determine the functional condition of the influence of soldering modes on the physical-mechanical characteristics of the compound. It has been shown the modeling of temperature fields in ANSYS 18.1. It has been established that the process of vacuum soldering should take place at a temperature of 1350°C for 15-20 min; the strength of the resulting compound is 390-420 MPa when the sample is stretched. The obtained information can be used as a theoretical basis for the development of the manufacturing process of the elements of the spaceship heat-shielding system.

The aim of the present paper is to test the synthesis of moulded metal composites (MMCs) with a metal matrix Al and a strengthening metal phase Fe of type „in vitro” and „hybrid”. There was a test done for the preparation of composites using a method similar to “capillary forming”, such as the metal matrix (melt of aluminium) was infiltrated in the space between the iron blasting grit which is the inversely option of solving similar problem in which problems the blasting grit (the strengthening phase) are forcibly implemented into the melts (the metal matrix). In this way the problem which needs to be solved, in which the melt is infiltrated between the space of the iron blasting grit, allows for the maximum reduction of the volume of the metal matrix on account of the strengthening phase. The experiments were conducted with laboratory equipment elaborated on the base of another equipment for "capillary forming" with extra vacuum, patent protected developed by the department ”Materials Science and Technology”. From the received moulded metal composites (MMCs) were establish areas of reaction between aluminium and the iron powder. The experiment produced significant results as received alloying between iron and aluminium at a relatively low temperature of melting of the iron in which there were received metal-composites structures of the type „in vitro” and „hybrid”, which were tested by metallography and micro-hardness analysis.