The variety of requirements for friction pairs requires the development of different technologies for the production of tribological materials with reference to the operation modes. Composite materials obtained by the casting technology have been successfully applied for the normalization of the thermomechanical state of the steam turbines. These composites consist of the matrix based on copper alloys reinforced with cast iron granules. Because the structure and properties of cast iron are determined by the conditions of their production studies have been conducted on determination of preparation conditions on grain structure and properties of the synthesized composite material. Using an upgraded unit for production of granules technological regimes were determined providing narrow fractional composition. It has been found that granules formed are characterized with typical microstructure of white cast iron containing perlite and ledeburite. Microhardness of pilot cast iron granules is characterized by high values (from 7450 up to 9450 MPa) and depends on the size of the fraction. Composite materials obtained using experimental granules had a microhardness of the reinforcing cast iron granules about 3500 MPa, and a bronze matrix – 1220 MPa, which is higher than the hardness of the composite material obtained by using the annealed DCL-1granules (2250 MPa). Metal base of experimental granules in the composite material has the structure of perlitic ductile iron with inclusions of ferrite not exceeding 10–15% and set around a flocculent graphite. As a result, the increase of physical-mechanical properties of finished products made of composite material is observed.

FEATURES OF MANUFACTURE OF COMPOSITE MATERIAL WITH MACROHETEROGENEOUS STRUCTURE WITH THE APPLICATION OF MAGNETIC FIELDSA. S. KALINICHENKO, V. A. SHEINERT, V. A. KALINICHENKO, A. G. SLUTSKY, Belarusian National Technical University, Minsk, Belarus, 65, Casted composite materials have found application in various branches of industrial production. However, there are still a number of problems related to the choice of optimal technology for their synthesis and the solution of which will help to achieve in practice high level of properties predicted by the theory and provide the control of interfacial interactions to enhance the stability of the structure and properties of composites. There is s need in additional research related to the development of new types of reinforcing elements, which will provide the raise in the level of performance of the composite. It is established that an important role plays not only the type of the matrix but also the chemical composition and microstructure of the reinforcing material. This would require research on optimization of technology for production of composite materials during the solid-liquid synthesis. The paper presents generalized results of experimental studies of peculiarities during the formation of composite materials on the basis of bronze and iron granules with the use of high-speed induction melting. As reinforcing phase iron granules DCHL with a diameter of about 1 mm were used.Keywords. Inductive heater, control unit, high speed melting, composite materials, macro-and microstructure. Литые композиционные материалы нашли применение в различных отраслях промышленного про-изводства [1][2][3]. Однако имеется еще ряд проблем, связанных с выбором оптимальной технологии их синтеза, решение которых обеспечит достижение на практике предсказываемых теорией свойств компо-зитов, управление межфазным взаимодействием для повышения стабильности структуры и свойств композитов. Необходимы и дополнительные исследования, связанные с разработкой новых видов арми-рующих элементов, которые позволят поднять уровень эксплуатационных характеристик композита. На-пример, композиционные материалы на основе меди разрабатываются, главным образом, для триботех-нического применения, так как они обладают повышенными антифрикционными свойствами [4].

Increasing the operational reliability of friction units is one of the priorities for mechanical engineering, which requires the creation of effective tribotechnical materials. First of all, this applies to sliding bearings, which are used in various friction units in a wide range of operating conditions and must meet a number of requirements: low coefficient of friction, high wear resistance and fatigue resistance, as well as good thermal conductivity, workability, corrosion resistance and machinability, low coefficient of linear expansion and low cost. It is problematic to satisfy these requirements in real conditions; therefore, different friction materials that are best suited to specific conditions have been developed. In particular, cast composite materials (LCM) have been developed, which have found application in various friction units operating in severe operating conditions. Currently, the theoretical foundations of the mechanics of reinforced composite materials are well developed, and a significant progress has been achieved in their material science. However, there are still many problems associated with the choice of optimal technology ensuring the achievement in practice of the predicted composites properties by theory, control of interfacial interaction to improve the stability of the structure and properties of CM, with the development of new types of reinforcing elements that can raise the level of composite performance.In the present work results of scientific and experimental studies on the development of casting technology (solid-liquid synthesis) for obtaining composite materials with macroheterogeneous structure have been summarized. The structures of composites are studied for different methods of synthesis, as well as for different chemical composition of cast iron granules. The prospects of using white vanadium cast iron granules as a reinforcing phase are shown.

The article discusses the results of manufacturing multicomponent consumable cathodes of vacuum electric arc evaporation plants. To obtain ingots of complex silicide as a raw material for the manufacture of target cathodes, it is proposed to use induction melting of pure metal charge materials in an argon atmosphere.The method made it possible to obtain ingots of complex silicide with a composition close to the calculated one and a density of at least 93 %. Further forming of the cathode takes place when controlling the powder fractions by their percentage ratio with a pressing force of at least 50 tons. The results obtained are compared with the SHS method of manufacturing cathodes of identical composition.