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The effect of electric-current pulses on the evolution of microstructure and texture in cryogenically rolled copper was determined. The pulsed material was found to be completely recrystallized, and the recrystallization mechanism was deduced to be similar to that operating during conventional static annealing. The microstructural changes were explained simply in terms of Joule heating. A significant portion of the recrystallization process was concluded to have occurred after pulsing; i.e., during cooling to ambient temperature. The grain structure and microhardness were shown to vary noticeably in the heat-affected zone (HAZ); these observations mirrored variations of temper colors. Accordingly, the revealed microstructure heterogeneity was attributed to the inhomogeneous temperature distribution developed during pulsing. In the central part of the HAZ, the mean grain size increased with current density and this effect was associated with the temperature rise per se. This grain size was slightly smaller than that in statically recrystallized specimens

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.

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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