Publications on the project |
019 Micromechanical properties of nanocrystalline titanium prepared by low-temperature rolling |
Authors: | L. S. Fomenko,a A. V. Rusakova, S. V. Lubenets, and V. A. Moskalenko | |
Summary: | It is found by the microindentation method that the defect structure of pure nanocrystalline titanium prepared by rolling at low temperatures is reasonably homogeneous. The texture created during the preparation of nanocrystalline samples makes itself evident in slight differences of mean microhardness values HV and the standard deviation measured on the rolling plane and on the plane perpendicular to the rolling direction in the temperature range 77–300 K. The relationship HV ≈ 3σ0.2 between the microhardness and the conventional yield stress is found to be applicable to nanocrystalline titanium. Titanium hardening as a result of grain refinement is attended by a noticeable decrease of its plastic ductility. | |
Keywords: | Nanocrystalline and coarse-grained titanium,
structural homogeneity, microhardness, ductility. | |
Edition: | LOW TEMPERATURE PHYSICS, vol. 36, 645 (2010). | | | 2010,
809-818,Russian |
019 Investigation of titanium nanostructure produced by deformation at low temperature |
Authors: | I.S. Braude, N.N. Galtsov, V.A. Moskalenko,
and A.R. Smirnov | |
Summary: | Bulk titanium with a grain size varied from nanometers
up to submicronic values was obtained by cryomechanical
treatment and annealing. Transmission electron
microscopy and x-ray diffraction investigations of the
nanostructure, defining unusual mechanical properties
of this new material, were carried out. The results of
comparative analysis of the structures formed during deformation
at temperatures close to liquid nitrogen and
room ones (where twinning and gliding activities are
different) show that a more effective grain fragmentation
at cryodeformation is determined by the mechanical
twinning. At the same time twinning has a randomization
effect on structure because of generation of a great
quantity of fragments with different orientation. Average
coherent-scattering regions (crystallite) size data L
and level of average internal microstrains Δε are measured.
It was supposed that a relatively low level of microstrains
Δε is the result of recovery process during
heating to room temperature after cryorolling. It is
shown, that the x-ray amorphous phase presented in nanocrystalline
titanium is not a true amorphous phase,
and it corresponds to coherent scattering regions with
sizes less than d ≤ 15 nm. | |
Keywords: | Nanostructure, titanium, twinning, cryomechanical
treatment, electron microscopy, x-ray diffraction. | |
Edition: | LOW TEMPERATURE PHYSICS | | | 2011,
1240-1250,Russian |
019 A study of corrosive-chemical properties and biocompatibility of submicrocrystalline titanium of BT1-0 grade |
Authors: | Volodymyr Filipenko, Katerina Sevidova, Ninel Diedukh, Svitlana Malyshkina, Anastasiya Simonova, Iryna Timchenko, Vladyslav Moskalenko | |
Summary: | A comparative assessment of ВТ1-0 samples with different crystalline structures according to criteria of their corrosive-electrochemical activity and results of medical-biological studies is given. It is shown that nano- and submicrocrystalline titanium preserves high biocompatibility indices, which are typical for macrocrystalline analogues. | |
Keywords: | biomaterials; nanostructural; macro- and submicrocrystalline titanium; implants | |
Edition: | Ortopaedics, traumatology and Prosthetics | | | 2011,
68-72,Russian |
019 Structure homogeneity of nanocrystalline titanium VT1-0. Low-temperature micromechanical properties |
Authors: | A.V. Rusakova, S.V. Lubenets, L.S. Fomenko, and V.A. Moskalenko | |
Summary: | Microhardness of the titanium VT1-0 samples with a grain size of 35 nm to 10 μm was measured over the temperature range 77–300 K. It is shown that the nanocrystalline samples produced by rolling at low temperature are sufficiently homogeneous and their structure is stable to thermal and mechanical effects. The interrelation between microhardness and grain size is described well by the Hall–Petch law the parameters of which depend on temperature. The temperature dependences of microhardness and Hall–Petch constant suggest that the microplastic deformation of titanium is of a thermally activated character and a dislocation nature no matter what the grain size is. | |
Keywords: | Titanium VT1-0, rolling at low temperature, nanocrystalline titanium, homogeneity of structure, microhardness, Hall–Petch law, thermally activated plasticity. | |
Edition: | LOW TEMPERATURE PHYSICS | | | 2012,
1240–1250,Russian |
019 The Acoustic Properties of Nanostructured and Fine crystalline Commercial Purity Titanium Alloy VT1-0 vithing the temperature Range 5-325 K |
Authors: | Yu.A. Semerenko, V.A. Moskalenko, A.R. Smirnov | |
Summary: | In the temperature range 5325 K, the temperature dependences of decrement, dynamic Young’s modulus in a nanocrystalline (grain size 30-50 nm) and fine crystalline (grain size 1 m) Ti are investigated. Acoustic measurements were carried out by flexural vibration technique at frequencies 1.43.7 kHz. The grain size was determined using electron microscopic technique.
The effect of plastic deforming 120-230% at 100 K and 290 K, annealing
at 525 K, 740 K and 940 K on parameters of low-temperature internal
friction and the related dynamic Young’s modulus is studied. | |
Keywords: | Nanocrystalline Ti, strength, plasticity, decrement,
dynamic Young’s modulus | |
Edition: | Metallofiz. Noveishie Tekhnol. | | | 2013,
497-506,Russian |
019 Low-temperature plastic deformation and strain hardening of nanocrystalline titanium |
Authors: | V.A. Moskalenko, A.R. Smirnov, and R.V. Smolianets | |
Summary: | The regularities of low-temperature plastic defor-mation of nanocrystalline (NC) commercial purity titanium VT1-0 have been studied in the quasi-static ten-sile experiments with average grain size ranged from d = 35 nm up to d = 2 μm in the temperature range 4.2 K < T < 395 K. The wide range of grain size distri-bution became possible due to using the method of cryomechanical grain fragmentation which com-bined rolling at liquid nitrogen temperature with sub-sequent annealing. It is found that the smooth curves are of a behavior wavy at temperatures T < 30 K, become serrated ones with decreasing temperature down to Tjump ≈ 22 K. The correlation between relative am-plitude of the stress jump Δσ/σ and strain hardening rate was found. A significant increase of ductility (especially at temperatures T < 140 K) under the condition of presence of a small fraction (≈ 15%) of submicron grains in NC titanium was observed. This can be explained by a combination of two processes: the dynamic grain growth under the influence of tensile stress and nanotwinning activation in the submicron grains. Discovered anomalous grain growth at cryogen-ic temperatures also favors for nanotwinning in the process of deformation. In the nanometer-sized grains (d < 50 nm) twins were not observed.
| |
Keywords: | Nanocrystalline titanium VT1-0, mechani-cal properties, strain hardening rate, twinning, electron microscopy. | |
Edition: | Low Temperature Physics | | | 2014,
1071-1082,Russian |
019 Mechanical Properties and Structural Features of Nanocrystalline Titanium Produced by Cryorolling |
Authors: | V. A. Moskalenko, V. I. Betekhtin, *, B. K. Kardashev, A. G. Kadomtsev,
A. R. Smirnova, R. V. Smolyanets, and M. V. Narykova | |
Summary: | Abstract—A broad spectrum of physicomechanical properties of VT10 nanocrystalline titanium produced by cryomechanical fragmentation of the grain structure using rolling at a temperature close to liquidnitrogen
temperature has been studied. The mechanism of grain refinement has been associated with grain fragmentation by twins. Exactly the twin nature of internal interfaces (crystallite boundaries) provides the thermal and
structural stability of nanocrystalline titanium produced by cryomechanical grain fragmentation in the temperature range to ~500 K. It has been assumed that the observed decrease in the titanium density due to cry
orolling is associated with a number of factors (high density of introduced dislocations, nanopore formation, and changes in titanium lattice parameters). | |
Keywords: | Nanocrystalline titanium VT1-0, cryomechanical grain fragmentation,
physicomechanical properties | |
Edition: | Physics of the Solid State | | | 2014,
1539-1545,Russian |
019 Bulk nanocrystalline titanium processing by cryomechanical grain fragmentation |
Authors: | V.A. Moskalenko | |
Summary: | | |
Keywords: | Bulk nanocrystalline titanium, deformation twinning, cryomechanical grain fragmentation | |
Edition: | Collective monograph "Nanosized systems and nanomaterials: research in Ukraine" | | | 2014,
37-42,Russian |
The events in the framework of the project |
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019 1. Physics of nanostructures Purpose: Expected results:Other (to increase production, improve working conditions, environmental improvement, energy savings, material savings, reduced equipment wear, increase productivity, improve efficiency of diagnosis and treatment, etc.) Stage 1: Stage 2: Stage 3: Stage 4: Stage 5:
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