Phase Transformation in Orthorhombic Ti2AlNb Alloys Under Severe Deformation

2004 ◽  
Vol 842 ◽  
Author(s):  
B. A. Greenberg ◽  
N. V. Kazantseva ◽  
V. P. Pilugin
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Phase Structure ◽  
Titanium Aluminides ◽  
Equilibrium Phase ◽  
Severe Deformation ◽  
Disordered Phase ◽  
Titanium Aluminum ◽  
B2 Phase ◽  
O Phase

ABSTRACTIt was found that severe plastic deformation of orthorhombic alloys caused phase transformations of the displacement type and those associated with a change in the degree of long-range order, namely B2→ω(B82 ), B2→B19 and B2→β (BCC) (in the case of alloy with initial B2-phase structure) and O→B19→A20 (initial O-phase structure, Ti2AlNb). Unlike to ordinary metals, severe plastic deformation of the titanium aluminum intermetallics leads to decreasing of the strength of the material. The B19 and A20 phases are metastable. They are absent in the equilibrium phase diagrams of the compounds under investigation. The formation of the disordered phase states with extensive sliding and having great plasticity under severe deformation makes possible to consider severe deformation as the way for increasing of plasticity of the titanium aluminides.

Severe plastic deformation and hydrogenation of the titanium aluminides

2011 ◽  
Vol 509 (38) ◽  
pp. 9307-9311 ◽  
Author(s):  
N.V. Kazantseva ◽  
N.V. Mushnikov ◽  
A.G. Popov ◽  
P.B. Terent’ev ◽  
V.P. Pilyugin
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Titanium Aluminides

scholarly journals Неравновесные диффузионные фазовые превращения в сплавах, обусловленные миграцией границ зерен и дислокаций

2019 ◽  
Vol 61 (2) ◽  
pp. 346
Author(s):  
И.К. Разумов ◽  
Ю.Н. Горностырев ◽  
А.Е. Ермаков
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Equilibrium Phase ◽  
Bulk Diffusion ◽  
Structural Instability ◽  
Regular Structures ◽  
Proposed Model ◽  
Nonequilibrium States ◽  
The Difference ◽  
And Diffusion

AbstractThe main scenarios of nonequilibrium diffusional transformations induced by moving defects (dislocations, grain boundaries) in alloys under severe plastic deformation are considered. It has been shown that the phase state locally changes in the area of a defect where thermodynamic properties of alloy are locally changed, and the attained state is frozen after the displacement of a defect due to the difference between the rates of bulk diffusion and diffusion on a defect. For this reason, an alloy shifts from the state of its thermodynamic equilibrium under treatment, thus different nonequilibrium states, such as the disordering of alloy, the dissolution of equilibrium phase precipitates, the appearance of nonequilibrium phases, and the formation of regular structures, are possible depending on the type of the system. These effects may take place if the treatment of an alloy is performed at moderate temperatures, when diffusion is frozen in the bulk and rather active on defects. The phenomena of phase and structural instability developing under severe plastic deformation at moderate temperatures are considered within the framework of the proposed model.

Graded phase structure in the surface layer of NiTi alloy processed by surface severe plastic deformation

2011 ◽  
Vol 64 (11) ◽  
pp. 1011-1014 ◽  
Author(s):  
T. Hu ◽  
L. Chen ◽  
S.L. Wu ◽  
C.L. Chu ◽  
L.M. Wang ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Surface Layer ◽  
Severe Plastic Deformation ◽  
Phase Structure ◽  
Niti Alloy

Severe plastic deformation of Al-1%Cu Alloy processed by a Simple Cyclic Extrusion Compression technique

2018 ◽  
Vol 1 (1) ◽  
pp. 77-90
Author(s):  
Walaa Abdelaziem ◽  
Atef Hamada ◽  
Mohsen A. Hassan
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Deformation Behavior ◽  
Cast Alloy ◽  
Surface Hardness ◽  
Grain Structure ◽  
Compression Technique ◽  
Cu Alloy ◽  
Cyclic Extrusion Compression

Severe plastic deformation is an effective method for improving the mechanical properties of metallic alloys through promoting the grain structure. In the present work, simple cyclic extrusion compression technique (SCEC) has been developed for producing a fine structure of cast Al-1 wt. % Cu alloy and consequently enhancing the mechanical properties of the studied alloy. It was found that the grain structure was significantly reduced from 1500 µm to 100 µm after two passes of cyclic extrusion. The ultimate tensile strength and elongation to failure of the as-cast alloy were 110 MPa and 12 %, respectively. However, the corresponding mechanical properties of the two pass CEC deformed alloy are 275 MPa and 35%, respectively. These findings ensure that a significant improvement in the grain structure has been achieved. Also, cyclic extrusion deformation increased the surface hardness of the alloy by 49 % after two passes. FE-simulation model was adopted to simulate the deformation behavior of the material during the cyclic extrusion process using DEFORMTM-3D Ver11.0. The FE-results revealed that SCEC technique was able to impose severe plastic strains with the number of passes. The model was able to predict the damage, punch load, back pressure, and deformation behavior.

TECHNOLOGIES FOR MANUFACTURING NANOSTRUCTURED SURFACES

2020 ◽  
Author(s):  
Андрей Дмитриевич Бухтеев ◽  
Виктория Буянтуевна Бальжиева ◽  
Анна Романовна Тарасова ◽  
Фидан Гасанова ◽  
Светлана Викторовна Агасиева
Keyword(s):  
Plastic Deformation ◽  
Surface Modification ◽  
Severe Plastic Deformation ◽  
Pressing Pressure ◽  
Pressure Treatment ◽  
Structured Surfaces ◽  
Nanostructured Surfaces ◽  
Angular Pressing ◽  
Multilayer Composites ◽  
Compaction Of Powders

В данной статье рассматривается применение и технологии получения наноструктурированных поверхностей. Рассмотрены такие методы как компактирование порошков (изостатическое прессование, метод Гляйтера), интенсивная пластическая деформация (угловое кручение, равноканальное угловое прессование, обработка давлением многослойных композитов) и модификация поверхности (лазерная обработка, ионная бомбардировка). This article discusses the application and technology for obtaining nano-structured surfaces. Methods such as compaction of powders (isostatic pressing, Gleiter method), severe plastic deformation (angular torsion, equal-channel angular pressing, pressure treatment of multilayer composites) and surface modification (laser treatment, ion bombardment) are considered.

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