The effect of conditions of crystallization in the course of the production of a bearing lining on the structure and wear of the B83 babbit has been studied. It is shown that the pressing of the melt being crystal lized makes it possible to form a homogeneous structure with fine crystals of the cubic SnSb phase. The babbit produced by liquid forging has the highest wear resistance.

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The behavior of a material in extreme regimes of operation in large constructions can be calculated with the use of modern software codes (ANSYS, DEFORM, LS-Dyna). However, they do not have a sufficient basis for the properties of metals and alloys. Therefore, it is necessary to input experimental mechanical properties of a studied material for an adequate description of a process. The present work aims to obtain the mechanical properties of babbit Sn 11 % Sb 5,5 % Cu in different structural states for a use in computer modeling in the software product Deform. As an object of the study, babbit of a chemical composition Cu 5.5 -6.5 wt. %, Sb 10 -12 wt. %, Sn -rest was chosen. Two different structural states of the alloy were obtained at different crystallization rates: the first by casting with air cooling and the second by casting with cooling in running water (rapid cooling). The mechanical properties were determined by upsetting tests according to standart. An Axiovert-100A microscope with the KSLite image processing program was used for optical metallography. A finite element simulation of a large-sized sliding bearing during operation in a two-dimensional formulation was carried out using the DEFORM-2D software. To evaluate the degree of destruction of the bearing during operation a scalar parameter of damage was determined using the model of metal damage accumulation during monotonic deformation. It is shown that rapid cooling leads to the formation of a structure with small intermetallic particles uniformly distributed in the matrix phase. Such a structure is characterized by enhanced mechanical properties, and computer simulation allows predicting its high wear resistance in a large-sized sliding bearing during operation. Современные пакеты прикладных программ (ANSYS, Deform, LS-Dyna) позволяют рассчитать поведение материала при предельных или аварийных режимах работы для конструкций любого размера. Однако они не имеют доста-точной базы по свойствам металлов и сплавов, поэтому для адекватного описания процесса необходимо вводить экспериментальные механические свойства исследуемого материала. Цель работы -получить механические свой-ства баббита Б83 с различным структурным состоянием, для использования при компьютерном моделировании в среде программного продукта DEFORM. В качестве объекта исследования выбран баббит Б83 химического состава Cu -5,5 -6,5 % вес., Sb -10 -12 %, Sn -ост. с двумя различными структурными состояниями, полученными при раз-ной скорости кристаллизации в результате литья в форму с охлаждением на воздухе и при литье в форму с охла-ждением проточной водой (скоростное охлаждение). Механические свойства определяли при испытаниях на осад-ку согласно ГОСТ 8817 -82. Оптическую металлографию проводили на микроскопе «Axiovert-100А», с программой обработки изображения KSLite. С помощью пакета прикладных программ DEFORM-2D было проведено компью-терное моделирование работы крупногабаритного подшипника скольжения в двумерной постановке. Для оценки степени разрушения подшипника определяли скалярный ...

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In this paper, computer simulation of the friction stir welding (FSW) of AlMg6Mn0.6 aluminum alloy sheet blanks by means of the DEFORM-3D software package is carried out to select the optimum pin geometry based on the calculation of the displacement and speed of displacement of the material points. Pins in the shape of a cylinder and a truncated cone with the cone angles of α =10, 20, and 30° were considered. The friction coefficient of 0.5 was assumed. Instrumental steel AISI-D2 was chosen as the material for the tool. To reduce the computation time and avoid the instability of solution, the model of welded blanks was built as a single body of 3 mm thickness and 40 and 30 mm length and width, respectively. The behavior of the AlMg6Mn0.6 alloy was described using the Johnson-Cook model. The FSW process was simulated at the tool moving speed v = 2 mm / s, rotation frequency ω =1000 rpm and axial force P = 25 kN. The initial temperature of the workpiece and the tool was 20°C. When welding the blanks, the conditions of heat exchange with the environment were set. The simulation results solution have shown that the flow of the material of the workpiece depends on the shape of the pin and is different over the thickness of the workpiece. The material in the lower area of the workpiece is practically not subjected to mixing for all values of the cone angle of the pin, in contrast to the middle and upper areas of the workpiece, where the material is noticeably mixed. Of all the tips considered, the most preferred for the FSW is a pin in the form of a truncated cone with the cone angle of 10°, since it provides good mixing in the plane of the workpiece, the maximum displacement of the material towards the root of the weld, and also allows one to get the most symmetrical seam.

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