Publications on the project |
0831 Quasicrystals - new atomic structure of solids and materials with unique complex of properties |
Authors: | Milman Yu.V., Iefimov M.O. | |
Summary: | The history of the discovery and ways to describe the structure of quasicrystals are shown. The analysis of the basic physical and mechanical properties of different types of quasicrystals is given. | |
Keywords: | The history of discovery, quasicrystal, structure, physical and mechanical properties | |
Edition: | Bulletin of NAS of Ukraine | | | 2012,
41-48,Ukrainian |
0831 Effect of starting powder properties on the structure and mechanical characteristics of Al–8Cr–1.5Fe alloy for high-temperature applications |
Authors: | O. D. Neikov, A. I. Sirko, N. P. Zakharova, M O. Iefimov, G. I. Vasil’eva, A. O. Sharovskii, A. V. Samelyuk, V. A. Goncharuk, R. K. Ivashchenko
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Summary: | A high-temperature Al–8Cr–1.5Fe alloy has been developed for applications in the range from room temperature to 300°C. Structural analysis shows that particles of the second phase in the water-atomized powders are finer and their number in the aluminum matrix is greater than that in the gas-atomized powders. The rods extruded from the water-atomized powders have much higher hardness, ultimate strength, and yield stress than those from the gas-atomized powders. An additional powder metallurgy operation—pulsed hot pressing—does not increase the strength of billets from either the water-atomized or gas-atomized powders. The alloy based on the water-atomized powder shows the maximum strength: 483, 332, and 261 MPa at 20, 190, and 300°C, respectively. | |
Keywords: | gas-atomized powders, water-atomized powders, high-temperature aluminum alloy, structure, strength, strain hardening | |
Edition: | Powder metallurgy | | | 2012,
35-43,Russian |
0831 Nanostructure Al-Fe-Cr alloys reinforced by quasicrystalline particles for high temperatures application |
Authors: | Yu.V. Milman, N.P.Zakharova, M.O.Iefimov , A.O. Sharovsky, M.O.Danilenko | |
Summary: | The features of structure and mechanical properties of nanostructured Al-Fe-Cr alloys with Ti and Zr alloying strengthened by quasicrystall particles were studied. Semi-finished products from these alloys were obtained without sintering by compacting powders produced by atomization of the melt by water under high pressure and subsequent extrusion of compacts in pre-evacuated and hermetic capsules. Investigations were carried out at 200С and after prolonged annealing at 300 0С. It was shown that Al matrix with grains 500 nm reinforced by quasicrystalline particles with size from 40 to 200 nm are formed in the rods of alloys on Al-Fe-Cr base obtained from wateratomized powders by developed technology. It is proved that plasticity of semi-finished alloys Al-Fe-Cr are practically independent from annealing time and have the level of 7.0% to 8.4%. S
Strength and hardness are some reduced. Thus, the developed alloys exceed the requirements of modern aviation industry.
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Keywords: | aluminum alloys, nanostructures, quasicrystalline particles, mechanical properties, structure, phase composition | |
Edition: | Electron microscopy and strength of materials | | | 2012,
25-32,Ukrainian |
0831 Quasicrystalls - a new class of solids with unique physical properties |
Authors: | Yu. V. Міlman, М. О. Iefimov, І.V.Goncharova | |
Summary: | This review covers the history of the discovery and methods of describing of structure for a new class of solids - quasicrystals. The best known and studied quasicrystals on Al base, however, also have been investigated the quasicrystals on the base of Ti, Zr, V, Nb, Mn, Zn, Mg and other metals. Examples of experimental studies of the structure of quasicrystalline materials by transmission electron microscopy and mechanical properties using indentation techniques, both at room and elevated temperatures are shown. The basic difference of quasicrystals from the crystalline solids, as well as the features of nano quasicrystals that releasing them into a separate class of materials are indicated. The most promising areas for practical applications of quasicrystals are given. | |
Keywords: | quasicrystal, structure, physical properties, the practical application | |
Edition: | Electron microscopy and strength of materials | | | 2012,
3-15,Russian |
0831 Quasicrystals - the new class of high-performance structural and functional materials. |
Authors: | Yu.V. Milman, M.O.Iefimov, N.P.Zakharova, A.O. Sharovsky | |
Summary: | The main types of quasicrystals and methods of their preparation are considered. The basic differences between the mechanical properties of quasicrystals, crystalline solids and nanoquasicrystals are described. Using of nanoquasicrystals for srtengthening of Al-Fe-Cr aluminum alloys and obtaining of protective thermal barrier coating from Al-Cu-Fe quasicrystalline powders are considered. Quasicrystallic powders obtained by high pressure water atomization. | |
Keywords: | quasicrystal, structure, the practical application | |
Edition: | Modern methods and technologies for creating and processing of materials. Collection of works of Physico-Technical Institute, Belarus National Academy of Sciences | | | 2013,
62-70,Russian |
0831 The influence of the structural state of the reinforcing nanoparticles on the mechanical properties of the alloy Al94Fe2.5Cr2.5Ti1 |
Authors: | Yu.V. Milman, N.P.Zakharova, M.O.Iefimov, M.O.Danilenko, A.O. Sharovsky, O.D.Neykov | |
Summary: | The effects of production conditions of Al94Fe2.5Cr2.5Ti1 extruded strips on its structure and mechanical properties were studied. Strips were obtained without sintering by compacting and subsequent extrusion of powders produced by water atomization technique. At extrusion temperature of 400 C the two-phase structure of the water atomized powders (Al matrix and reinforcing nanoquasicrystaline phase) remained unchanged. Further increase in extrusion temperature reduced the content of quasicrystalline reinforcing particles gradually; the part of them transformed into a crystalline state. Quasicrystalline particles are completely absent in the material obtained at extrusion temperature of 450° C. The results of mechanical test give reason to assume that the mechanical properties of this alloy are mainly determined by the structural state of the reinforcing particles (quasicrystalline or crystalline). Strengthening of aluminum matrix by nanoquasicrystalline particles provides the plasticity of the alloy above 5%. On the contrary, strengthening by intermetallic particles reduces the plasticity of the alloy to values <1%. This result confirms the idea regarding significant plasticity of quasicrystals at local loading. This local plasticity allows relaxing the stresses arisen in aluminum matrix at deformation of the alloy. | |
Keywords: | nanoquasicrystals, aluminum alloy, structure, phase composition, strength, plasticity. | |
Edition: | Electron microscopy and strength of materials, Kiev 2013, vol. 19 | | | 2013,
36-43,Russian |
0831 Structure and mechanical properties of Al-Fe-Cr alloys for elevated temperatures, reinforced by nanoquasicrystalline particles additionally alloyed by Ti, Mo and Nb |
Authors: | Yu.V. Milman, N.P.Zakharova, M.O.Iefimov, M.O.Danilenko, A.O. Sharovsky, A.V. Samelyk, V.A. Goncharyk, O.D.Neykov | |
Summary: | The effect of additional alloying by Ti, Nb and Mo to the increase of operating temperature of nanostructured Al-Fe-Cr alloys with aluminum matrix reinforced by quasicrystalline particles were studied . Rods from investigated alloy with a diameter of 6 mm were obtained by extrusion of water-atomized powders without sintering. Due to designed regimes, the two-phase structure of powders (aluminum matrix reinforced by nanoquasicrystalline particles) was obtained in all studied compositions. All investigated alloys exhibit the high thermal stability. Alloy Al94Fe2,5Cr3Mo0,5Ti0,5 is the most stable at the level of hardness during the annealing at 400 С. The highest level of strength at 400 0С show the alloys additionally alloyed by Nb. | |
Keywords: | nanoquasicrystals, aluminum alloys, structure, phase composition, strength ,plastisity. | |
Edition: | Electron microscopy and strength of materials 2014 | | | 2014,
18-26,Russian |
The events in the framework of the project |
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0831 Milman Yuly V.Corresponding Member of the NAS of Ukraine Head of Department +380444243181
0831 3.2. Scientific and technological foundations of permanent joints materials using nanostructured layers and severe plastic deformation in the joint zone Purpose: Expected results:Release of new product: material Stage 1:Модернізація технології отримання методом водоструменевого диспергування розплаву порошків жароміцних Al сплавів, зміцнених квазікристалічними частками. Вибір хімічного складу сплавів на основі системи Al-Cr-Fe-T, де Т – перехідні металип Stage 2:Оптимізація технології компактування порошків та виготовлення деформованих напівфабрикатів. Stage 3:Дослідження структури, хімічного та фазового складу отриманих напівфабрикатів і їх зварних з‘єднань. Виготовлення порошкових напівфабрикатів скорегованого хімічного складу при кімнатній та підвищених температурах та визначення їх механічних властивостей при кімнатній та підвищених температурах. Stage 4:Встановлення закономірностей хімічний склад – технологія виготовлення – структура – механічні властивості напівфабрикатів - зварюваність вивчених сплавів (сумісно з ІЕЗ НАНУ). Stage 5:Дослідження структури та механічних властивостей зварних з’єднань (сумісно з ІЕЗ НАНУ).
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