Yu. N. Koval
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View article: The fracture toughness of molybdenum at different grain sizes under and since brittle-ductile transition: computer modeling and experiment
The fracture toughness of molybdenum at different grain sizes under and since brittle-ductile transition: computer modeling and experiment Open
The sharp growth of the fracture toughness after brittle-ductile transition happens at grain sizes approximately equal to the plastic zone size. Here we analyze the influence of the grain boundary on the evolution of the ensemble of disloc…
View article: Some Relationships for the Inter-Atomic Potential Models Describing the Interaction between the Chemically Different Type Atoms
Some Relationships for the Inter-Atomic Potential Models Describing the Interaction between the Chemically Different Type Atoms Open
Three-parametric Lenard-Jones and Morse interatomic potentials are the simplest ones, which that can be used to obtain thermophysical properties of the liquid and solid substances. Upon adjusting the model parameters to real substance prop…
View article: Investigation at Aging of Functional Properties of Alloy of Cu–Al–Mn System Alloyed with Co
Investigation at Aging of Functional Properties of Alloy of Cu–Al–Mn System Alloyed with Co Open
Проведено дослідження зміни фізико-механічних характеристик і величини деформації за мартенситним механізмом термообробленого стопу Cu-30,3 ат.% Al-4,5 ат.% Mn-5,1 ат.% Co. Витоплений стоп піддавали гомогенізувальному відпалу за 973 К прот…
View article: Micromagnetic modeling of magnetization distribution caused by internal twin microstructure of NiMnGa ferromagnetic shape memory alloys
Micromagnetic modeling of magnetization distribution caused by internal twin microstructure of NiMnGa ferromagnetic shape memory alloys Open
In our present publication we will continue studying the effects of the magnetostatic energy on the magnetization behavior of FMSMAs recently started in some our publications. Our method is based on the direct minimization of our new micro…
View article: Computational Methods for Determining Martensitic Transformation Characteristics in Binary and Multicomponent Functional Materials
Computational Methods for Determining Martensitic Transformation Characteristics in Binary and Multicomponent Functional Materials Open
The theory of evolutionary algorithms for predicting crystal structures allows to calculate the maximum content of the second alloying component in binary materials, at which martensitic transformation can take place.As calculated, in the …
View article: Laser Welding of Ti–Ni Shape Memory Alloy for Medical Application
Laser Welding of Ti–Ni Shape Memory Alloy for Medical Application Open
from 45°С to 20°С.Shape recovery in material of welded joints is observed at temperature range of 60-100°С.The obtained results allow determining the ranges of values in which it is expedient to optimize the parameters of laser treatment m…
View article: Martensitic Transformation in Quenched Hf–Nb Alloys
Martensitic Transformation in Quenched Hf–Nb Alloys Open
Martensitic transformation and shape memory effect are investigated in Hf-Nb alloys.Niobium content varies in a range of 15 at.% to 50 at.%. Prior to investigation samples are quenched in water.Phase composition, microstructure and functio…
View article: Corrosion-fatigue failure of tractor trailers metal materials in aggressive environments
Corrosion-fatigue failure of tractor trailers metal materials in aggressive environments Open
The processes of corrosion-fatigue failure of materials in contact with mineral fertilizers are insufficiently studied. As a result of joint influence of atmospheric corrosion and mechanical loads, about 70 to 80 % of machine parts get out…
View article: Micromagnetic Modeling of the Magnetization Behavior of NiMnGa FMSMAs
Micromagnetic Modeling of the Magnetization Behavior of NiMnGa FMSMAs Open
The model calculations of the magnetization curves for the internally twinned NiMnGa ferromagnetic shape memory alloy are performed at the different volume fractions of twin variants. The method is based on the direct minimization of our n…
View article: Magnetomechanical Effects in the Elastic Polymer Composites Containing Ferromagnetic Powder Particles
Magnetomechanical Effects in the Elastic Polymer Composites Containing Ferromagnetic Powder Particles Open
In the present work, a detailed thermodynamic consideration for the magnetic free energy of the composite material consisting of the ferromagnetic powder particles embedded into a polymer matrix is given. We estimate their magnetostatic in…
View article: Joining parts from shape-memory alloy of Cu–Al system and structural metals by arc-contact welding
Joining parts from shape-memory alloy of Cu–Al system and structural metals by arc-contact welding Open
Shape-memory alloys changing part configuration at heating, as well as preserving their elasticity at up to 8-10 % deformation, are becoming ever wider applied in industrial products and apparatuses as thermally-activated elements.Commerci…
View article: Joining parts from shape-memory alloy of Cu–Al system and structural metals by arc-contact welding
Joining parts from shape-memory alloy of Cu–Al system and structural metals by arc-contact welding Open
Сплавы с эффектом памяти формы, изменяющие конфигурацию детали при нагревании, а также сохраняющие упругость при деформации до 8...10 %, находят все большее применение в промышленных изделиях и аппаратах в качестве термоактивируемых элемен…
View article: Zr—Nb-Based Alloys – Promising Functional Materials
Zr—Nb-Based Alloys – Promising Functional Materials Open
В процессе поиска новых функциональных сплавов была изучена система Zr—Nb. Выполнены исследования на наличие мартенситного превращения (МП) и эффекта памяти формы, изучены особенности состава с помощью микроструктурных и рентгенографически…
View article: Mechanical Testing of the Shape-Memory Materials Synthesized by a Plasma-Spark Method
Mechanical Testing of the Shape-Memory Materials Synthesized by a Plasma-Spark Method Open
Испытания на сжатие были выполнены при комнатной температуре для образцов сплавов Ni49,0—Mn28,5—Ga22,5 (ат.%) и Ni63—Al37 (ат.%), как для выплавленных, так и полученных плазменно-искровым методом (ПИМ). Для обеих систем пластичность ПИМ-об…
View article: Features of Hysteresis of Martensitic Transformations in Cu—Al—Mn Alloys
Features of Hysteresis of Martensitic Transformations in Cu—Al—Mn Alloys Open
УкраинаИсследована связь между частичным распадом аустенита и характеристиками термоупругого мартенситного превращения в сплавах, содержащих 12-13% масс.Al и 6-10% масс.Mn.Уменьшение гистерезиса мартенситного превращения Т на ранних стади…
View article: Resistance welding of shape-memory copper-aluminium alloy
Resistance welding of shape-memory copper-aluminium alloy Open
Cu-Al based shape-memory alloys (SMA) are an attractive replacement for expensive SMA of Ti-Ni system in fasteners, thermal automatic device activators, and superelastic elements of instrumentation.Therefore, the problem of joining the lat…
View article: Atomic Ordering and Parameters of Martensitic Transformation in Fe-based Alloys
Atomic Ordering and Parameters of Martensitic Transformation in Fe-based Alloys Open
Evolution of martensitic transformation (MT) start temperatures, hysteresis and shape recovery in Fe-Ni, Fe-Ni-Sm and Fe-Pt alloys with ordering has been studied. Atomic ordering and position disordering (alloying) are determined as factor…
View article: Phase Transformations and Shape Memory Behavior in Ni3Ta-based Intermetallics
Phase Transformations and Shape Memory Behavior in Ni3Ta-based Intermetallics Open
© 2015 The Authors. Stoichiometric Ni3Ta intermetallic compound undergoes martensitic transformation [1] and exhibits shape memory behavior at elevated temperatures [2]. The present paper is dedicated to the influence of alloying by Nb and…
View article: High Entropy Shape Memory Alloys
High Entropy Shape Memory Alloys Open
One of the sources for the improvement in shape memory behavior is the arrest of the irreversible plastic deformation in the process of accumulation of the reversible martensitic deformation. In this regard, so-called high entropy alloys (…