Crystal Structure of Martensite and Orientation Relationships During Thermoelastic Martensitic Transformations in Ni-Mn-Based Alloys

Orientation relationships (OR’s) for the B2↔L10 thermoelastic martensitic transformations (TMT’s) in Ni50Mn50 alloy were determined by transmission and scanning electron microscopy methods, which differ from the Bain OR’s previously accepted for them. Electron microscopic studies have shown that L10 martensite has a hierarchic morphology of packets of thin plates of pairwise twinned crystals with flat boundaries of habit close to {110

Microstructure and Thermoelastic Martensitic Transformations in Ni-Mn-Al Based Alloys

The physical properties and structure, thermoelastic martensitic transformations (TMT’s) of Ni50Mn50

Comparative Electron-Microscopic Study of Shape Memory Alloys of Systems Cu-Ni-Al and Ni-Mn-Al

The microstructure of Cu-Ni-Al and Ni-Mn-Al alloys in a wide range of chemical compositions has been studied by transmission and scanning electron microscopy methods, diffraction of electrons and X-rays. The phase composition of all the investigated alloys and the mechanism of the fracture under deformation have been determined.     Keywords: thermoelastic martensitic transformation, brittleness, fractography, longperiod lattice, electron-microscopic studies

Damage-failure transition in titanium alloy Ti-6Al-4V under dwell fatigue loads

The role of structural mechanisms responsible for the consequent staging of damage-failure transition as the combination and continuity of ductile and creep kinetics of the structure evolution and the modeling in dwell fatigue regime. Damage-failure transition is considered as critical phenomena, the structural-scaling transition, when the damage develops as specific phase with characteristic stages: nucleation of new phase and the phase growth kinetics. In the case of dwell fatigue, the nucleation stage is associated with slip localization, faceting, voids and microcrack initiation; the phase growth kinetics has the relation to specific non-linearity of the free energy release responsible for the staging of damage-failure transition. Statistically based phenomenological model of damage-failure transition specified the links of macroscopic material parameters with structural parameters responsible for the influence of microstructure on the structure sensitive mechanical properties. The developed conception of modeling of Ti alloys based on the duality of damage kinetics in dwell fatigue loads allowed us to propose the strategy of structural study to provide in perspective the links of structural parameters of /phases with phenomenological parameters responsible for different mechanisms of damage accumulation at LCF and stress hold regimes

A sensitive search for dark energy through chameleon scalar fields using neutron interferometry

The physical origin of the dark energy, which is postulated to cause the accelerated expansion rate of the universe, is one of the major open questions of cosmology. A large subset of theories postulate the existence of a scalar field with a nonlinear coupling to matter chosen so that the effective range and/or strength of the field is greatly suppressed unless the source is placed in vacuum. We describe a measurement using neutron interferometry which can place a stringent upper bound on chameleon fields proposed as a solution to the problem of the origin of dark energy of the universe in the regime with a strongly-nolinear coupling term. In combination with other experiments searching for exotic short-range forces and laser-based measurements, slow neutron experiments are capable of eliminating this and many similar types of scalar-field-based dark energy models by laboratory experiments.NSF grant PHY-1068712Indiana University Center for the Exploration of Energy and MatterIndiana University Center for Spacetime SymmetriesCanadian Excellence Research, NSERC Discovery and CREATE Progra

OBTAINING OPTIMAL MECHANICAL PROPERTIES OF Cu-Al-Ni-(B) ALLOYS WITH THERMOELASTIC MARTENSITE TRANSFORMATION USING HIGH TEMPERATURE THERMOMECHANICAL TREATMENT

Впервые проведена работа по горячей деформации массивных образцов поликристаллических α+β-сплавы системы Cu-Al-Ni эвтектоидных составов, в том числе легированных бором Cu, Al (10-11 мас.%), Ni (3-4 мас.%) и B (0.2–0.3 масс.%). Было также проведено комплексное исследование микроструктуры и фазового состава сплавов, подвергнутых многоступенчатой высокотемпературной термомеханической обработке (ВТМО) ковкой и прокаткой. Были получены и проведены механические испытания на одноосное растяжение тонких деформированных полос толщиной (h ≈ 1 мм), длиной (l ≈ 100 мм), шириной (b ≈ 15 мм) сплавов в мелкозернистом состоянии, что обеспечило повышение функциональных прочностных и пластических характеристик. Предложена схема ВТМО объемных сплавов Cu-Al-Ni, в том числе легированных бором.For the first time, work was carried out on hot deformation of massive samples of polycrystalline α+β-alloys of the Cu-Al-Ni system of eutectoid compositions, including those doped with boron Cu, Al (10-11 wt.%), Ni (3-4 wt.%) and B (0.2–0.3 wt.%). A comprehensive study of the microstructure and phase composition of alloys subjected to multi-stage high-temperature thermo-mechanical treatment (HTMT) by forging and rolling was also carried out. Mechanical tests for uniaxial tension of thin deformed strips with thickness (h ≈ 1 mm), length (l ≈ 100 mm), width (b ≈ 15 mm) of alloys in a fine-grained state were obtained and carried out, which provided an increase in functional strength and plastic characteristics. A scheme for HTMT of bulk Cu-Al-Ni alloys, including those doped with boron, has been proposed.Текст аннотации на английском языке.Работа выполнена за счет средств Российского научного фонда (проект № 22-72-00056, https://rscf.ru/project/22-72-00056/, ИФМ УрО РАН)

STUDY OF PHASE TRANSFORMATIONS OF THE MICROSTRUCTURE OF ALLOYS BASED ON BINARY ALLOY OF STOICHIOMETRIC COMPOSITION Ni-Mn

Микроструктуру сплава номинального состава Ni50Mn50 изучали методами микроскопии видимого света (ОМ), сканирующей (СЭМ) и просвечивающей электронной микроскопии (ПЭМ). Анализ изображений выполнен в среде программного обеспечения SIAMS 800 и нейросети SIAMS AIM. Изучена микроструктура сплава в мартенситном состоянии и после естественного старения. Фазовый состав и параметры кристаллических решеток фаз устанавливали методом рентгеноструктурного фазового анализа (РФСА) и дифракции обратно рассеянных электронов (EBSD).The microstructure of the alloy with the nominal composition Ni50Mn50 was studied by visible light microscopy, scanning microscopy, and transmission electron microscopy. Image analysis was performed in the SIAMS 800 software environment and the SIAMS AIM neural network. The microstructure of the alloy in the martensitic state and after natural aging was studied. The phase composition and crystal lattice parameters of the phases were determined by X-ray diffraction phase analysis and electron backscatter diffraction.Работа выполнена в рамках государственного задания МИНОБРНАУКИ России (Шифр «Структура» Г.р. № 122021000033-2). Работа выполнена с использованием оборудования ЦКП «Испытательный центр нанотехнологий и перспективных материалов» ИФМ УрО РАН. При финансовой, технической и программной поддержке ООО «СИАМС»

Plants with genetically encoded autoluminescence

Autoluminescent plants engineered to express a bacterial bioluminescence gene cluster in plastids have not been widely adopted because of low light output. We engineered tobacco plants with a fungal bioluminescence system that converts caffeic acid (present in all plants) into luciferin and report self-sustained luminescence that is visible to the naked eye. Our findings could underpin development of a suite of imaging tools for plants

METHOD OF PRODUCING NANOCRYSTALLINE COATS BASED ON NANOCRYSTALS OF LITHIUM OR SODIUM FLUORIDE

FIELD: nanotechnologies. SUBSTANCE: invention aims at producing nanocrystalline coats based on lithium or sodium fluoride on various substrates. The aforesaid coats are produced by a power spraying beam representing ionic cyclotron beams of He⁺ or N³⁺ ions used to irradiate, in cyclotron target chamber in vacuum, the mother crystals of lithium or sodium fluoride arranged at the angle of 10 to 15° relative to the ion beam. The irradiation is proceeded at constant heating by means of contact platinum electrode till obtaining fluences of 5·10¹⁵t to 10⁷ ion/cm². EFFECT: production of nanocrystalline solid or insular coats based on lithium or sodium fluoride on various substrates. 4 cl, 6 dwg.Изобретение предназначено для получения нанокристаллических покрытий на основе нанокристаллов фторида лития или фторида натрия на различных подложках. Сущность изобретения: нанокристаллические покрытия на основе нанокристаллов фторида лития или фторида натрия получают с использованием энергетического распыляющего пучка, в качестве которого применяют ионные циклотронные пучки ионов гелия He⁺ или ионов азота N³⁺, которыми облучают в мишенной камере циклотрона в вакууме исходные кристаллы фторида лития или фторида натрия, которые располагают под углом 10-15° относительно пучка ионов и облучают до флюенсов 5·10¹⁵-10⁷ ион/см² при постоянном нагреве в течение всего процесса облучения с помощью контактного платинового электрода. Техническим результатом изобретения является получение нанокристаллических покрытий на основе нанокристаллов фторида лития или фторида натрия на различных подложках с высокой адгезией к подложкам и возможность создания нанокристаллических покрытий сплошного или островкового типа. 3 з.п. ф-лы, 6 ил