Structural-scaling transitions and thermodynamic and kinetic effects in submicro-(nano-)crystalline bulk materials

Naimark, Oleg; Bayandin, Yuriy; Leontiev, V.A.; Panteleev, Ivan; Plekhov, O.

doi:10.1016/j.physme.2009.12.005

Cited by 13 publications

(16 citation statements)

References 16 publications

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“…The results above are consistent with those obtained by other authors [2], namely: mechanical characteristics of titanium improve with smaller size of grains, and the grain-like nature of this metal influences its ability to absorb applied mechanical energy. The fracture of UFG titanium is accompanied by a distinct localization of deformations.…”

Section: Resultssupporting

confidence: 92%

“…To evaluate such defects, one should use the process characteristics which accompany degradation of defects from their origin to fatal failure. Contemporary infrared (IR) imagers are characterized by a remarkable set of technical parameters, such as high temperature resolution, high frame frequency and remote operation thus allowing their use for analyzing defect accumulation and damage development in the process of mechanical loading of materials [1,2]. A number of studies to predict fracture of materials have been done recently on ultrafine-grained (UFG) metals subjected to mechanical stimulation by thermographically analyzing their dynamic temperature response [2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

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Analyzing Deformation and Damage of VT1-0 Titanium in Different Structural States by Using Infrared Thermography

et al. 2016

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This study is devoted to the comparison of strength characteristics in the process of deformation and damage of axially strained VT1-0 titanium in the ultrafinegrained (UFG) and coarse-grained (CG) states. The temperature distributions on the surface of titanium specimens were recorded by means of IR thermography. The VT1-0 titanium in UFG state formed by applying severe plastic deformation is characterized by twice the yield stress and strength limit but half the deformation limit compared to CG titanium. The fracture of CG titanium is accompanied by local powerful generation of heat, while, in UFG titanium, the damage nuclei are less intense and more evenly distributed over the fracture cross-section. The titanium in UFG state, being deformed, utilizes structural channels of energy absorption more efficiently than in the CG state by involving the whole deformed volume in the fracturing process.

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Section: Resultssupporting

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Analyzing Deformation and Damage of VT1-0 Titanium in Different Structural States by Using Infrared Thermography

et al. 2016

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“…A specific volume, which is occupied with UFG structure, influences on the HEL and the spall strength of alloys. Research of deformation localization and fracture mechanisms of NS and UFG alloys was investigated by a combination of structure-sensitive methods [1,2,[22][23][24][25][26][27]. The high sensitivity of modern infrared (IR) thermal vision systems in combination with the opportunity of noncontact continuous temperature and strain measurements gives us important information on processes of damage and fracture.…”

Section: Nanomechanicsmentioning

confidence: 99%

“…The high sensitivity of modern infrared (IR) thermal vision systems in combination with the opportunity of noncontact continuous temperature and strain measurements gives us important information on processes of damage and fracture. Recently, it has been shown that UFG titanium has a peak of an internal friction at temperatures of 450-500 C, which results from the processes of recovery and recrystallization [22]. Experimental data were obtained about the deformation and thermal characteristics of the UFG and CG VT1-0 alpha titanium alloy and E110 zirconium alloy [26][27][28].…”

Section: Nanomechanicsmentioning

confidence: 99%

Mechanical Behavior of Nanostructured and Ultrafine-Grained Metal Alloy under Intensive Dynamic Loading

Skripnyak¹,

Skripnyak²

2017

Nanomechanics

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Researches of the last years have allowed to establish that the laws of deformation and fracture of bulk ultrafine-grained (UFG) and coarse-grained (CG) materials are various both in static and in dynamic loading conditions. The influence of average grain size on the yield stress, the tensile strength, and the compression strength was established for metal alloys with a face-centered cubic (FCC), a body-centered cubic (BCC), and a hexagonal close-packed (HCP) structures. The study of the microstructure of the alloys after severe plastic deformation (SPD) by the electron backscatter diffraction (EBSD) technique showed the presence of a bimodal grain size distribution in the UFG alloys. Metal alloys with a bimodal grain size distribution possess a negative strain rate sensitivity of the yield stress and higher ductility at quasi-static strain rates. In this chapter, we will discuss the regularities of deformation at high strain rates, damage, and fracture of ultrafine-grained alloys.

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“…Эти предположения впер-вые были высказаны в работе [20] и получили свое развитие в работах [17,18,21], по-священных развитию статистико-термодинамической модели поведения среды с дефек-тами в поле приложенных напряжений. С использованием современного эксперимен-тального оборудования впервые показано самоподобное строение зон локализации деформации при квазистатическом растяжении сильвинита.…”

Section: результаты экспериментовunclassified

Features of Strain Localization in Sylvinite Under Tension

Panteleev¹,

Plekhov²,

Naimark³

et al. 2015

PNRPU MB

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Настоящая работа посвящена исследованию пространственно-временной локализа-ции деформации при прямом одноосном растяжении сильвинита с использованием ме-тода корреляции цифровых изображений и метода акустической эмиссии. Для реализа-ции схемы прямого одноосного растяжения использовано специальное реверсивное уст-ройство, в котором бетонируются образцы сильвинита. Последовательно сфотографиро-ванные изображения боковой поверхности образцов были использованы для восстанов-ления распределения полей компонент вектора перемещений и тензора деформаций на боковой поверхности образцов сильвинита при одноосном квазистатическом растяжении. В результате анализа полученных данных установлено, что процесс деформирования реализуется в виде двух последовательно следующих форм пространственно-временной локализации: системы эквидистантно расположенных стационарных очагов локализован-ной деформации и одиночной стационарной диссипативной локализованной структуры. Материал вне полос локализованной деформации находится в недеформированном состоянии, также в результате одноосного квазистатического растяжения наблюдаются как полосы локализованной деформации растяжения, так и сжатия. Переход от одной формы локализации к другой происходит в окрестности максимума напряжения и сопро-вождается резким уменьшением концентрационного параметра. Концентрационный па-раметр характеризует степень взаимодействия дефектов различных масштабных уров-ней посредством их упругих полей и может быть оценен по данным акустической эмис-сии. Анализ зависимости пространственного периода полос локализованной деформации от размера расчетной ячейки показал, что полосы локализованной деформации имеют самоподобное строение и процесс деформирования локализован по границам зерен минералов, слагающих образец. © ПНИПУ Ключевые слова:локализация деформации, акустическая эмиссия, прямое растяжение, концентрационный параметр, метод корреляции цифровых изображений  Пантелеев Иван

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Structural-scaling transitions and thermodynamic and kinetic effects in submicro-(nano-)crystalline bulk materials

Cited by 13 publications

References 16 publications

Analyzing Deformation and Damage of VT1-0 Titanium in Different Structural States by Using Infrared Thermography

Analyzing Deformation and Damage of VT1-0 Titanium in Different Structural States by Using Infrared Thermography

Mechanical Behavior of Nanostructured and Ultrafine-Grained Metal Alloy under Intensive Dynamic Loading

Features of Strain Localization in Sylvinite Under Tension

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