Аномальный рост зерен в криогенно-деформированной меди

Structural changes in cryogenically deformed copper during long-term (up to two years) room-temperature ageing were investigated. It is found that the structure formed under high (e=8.2) cryogenic deformation is unstable and is characterized by abnormalous grain growth. It is shown that the grain growth is preceded by a long (up to a year) incubation period. It is revealed that the structure rapidly losses stability with an increase in accumulated cryogenic strain

Nanostructure and properties of a Cu-Cr composite processed by severe plastic deformation

A Cu-Cr composite was processed by severe plastic deformation to investigate the role of interphase boundaries on the grain size reduction mechanisms. The as-deformed material exhibits a grain size of only 20nm. This gives rise to a dramatic increase of the hardness. Some deformation induced Cu super saturated solid solutions were clearly exhibited and it is shown that they decrease the hardness. The formation of such supersaturated solid solution and their influence on the mechanical properties are discussed

Влияние криогенной прокатки на микроструктуру и механические свойства меди

The effect of cryogenic rolling on the structure and mechanical properties of copper was studied. The grain structure evolution was shown to be mainly governed by the geometrical effect of the imposed strain whereas the contribution of the mechanical twinning and grain subdivision was found to be not significant. The analysis of the developed texture demonstrated that the plastic flow arises mainly from conventional {111} slip. The cryogenic rolling was shown to increase strength and decrease ductility and both effects might be attributed to the substructure

Формирование микроструктуры в ходе криогенной прокатки меди

Проведена тщательная аттестация микроструктуры и механических свойств меди, подвергнутой различной степени криогенной прокатки. Показано, что эволюция зеренной структуры, в основном, определялась геометрическим эффектом деформации. На основе анализа текстурных данных был сделан вывод, что криогенные условия деформации не привели к фундаментальному изменению характера пластического течения, и основным механизмом деформации было дислокационное {111} скольжение. Установлено, что криогенная прокатка приводит к существенному увеличению прочности и некоторому снижению пластичности

Влияние криогенной осадки на микроструктуру катаной мелкозернистой меди

Исследована возможность существенного измельчения зерен в технически чистой меди путем криогенной осадки. Установлено, что эволюция структуры в целом определялась сплющиванием исходных зерен в ходе деформации. Анализ текстурных данных и спектра разориентировок показал, что основным механизмом пластического течения являлось обычное {111} дислокационное скольжение при несущественном вкладе механического двойникования

Криогенная деформация меди

The effect of cryogenic deformation on the structure refinement of copper was studied

Моделирование и оптимизация процесса перемещения грузов в логистической тран- портной системе

Network model and algorithm for the solution of optimization problem concerning cargo transportation process within multi-terminal network in accordance with several efficiency criteria of transportation system operation have been constructed and elaborated in the paper.The paper gives the algorithm that makes it possible to trace routes and cyclic routes of maximum carrying capacity of a transportation flow.Построена сетевая модель и разработан алгоритм решения задачи оптимизации процесса перемещения грузов в многополюсной трайспортной сети по нескольким критериям эффективности функционирования транспортной системы.Приведен алгоритм отыскания маршрутов и циклических маршрутов максимальной пропускной способности транспортного потока

Optimization of the magnetic properties of FePd alloys by severe plastic deformation

A FePd alloy was nanostructured by severe plastic deformation following two different routes: ordered and disordered states were processed by high pressure torsion (HPT). A grain size in a range of 50 to 150 nm is obtained in both cases. Severe plastic deformation induces some significant disordering of the long range ordered L10 phase. However, Transmission Electron Microscopy (TEM) data clearly show that few ordered nanocrystals remain in the deformed state. The deformed materials were annealed to achieve nanostructured long range ordered alloys. The transformation proceeds via a first order transition characterized by the nucleation of numerous ordered domains along grain boundaries. The influence of the annealing conditions (temperature and time) on the coercivity was studied for both routes. It is demonstrated that starting with the disorder state prior to HPT and annealing at low temperature (400\degree C) leads to the highest coercivity (about 1.8 kOe)

Annealing behavior of cryogenically-rolled Cu-30Zn brass

The static-annealing behavior of cryogenically-rolled Cu-30Zn brass over a wide range of temperature (100-900 °C) was established. Between 300 and 400 °C, microstructure and texture evolution were dominated by discontinuous recrystallization. At temperatures of 500 °C and higher, annealing was interpreted in terms of normal grain growth. The recrystallized microstructure developed at 400 °C was ultrafine with a mean grain size of 0.8 μm, fraction of high-angle boundaries of 90 pct., and a weak crystallographic texture

Об эффективности криогенной деформации для измельчения микроструктуры меди

In the work, we studied and compared the microstructures of commercially pure copper subjected to the same strain at room temperature and at liquid-nitrogen temperature. It is found that at rather low plastic strain (slump, e=1.0), cryogenic temperature assists the activation of mechanical twinning and somewhat accelerates the formation of deformation boundaries. At high plastic strain (high-pressure shear, e=8.4), cryogenic temperature adds too little to microstructure refinement