scholarly journals Analysis of the Structural State Formed in Titanium at the Final Severe Plastic Deformation Stage

2020 ◽  
Vol 121 (10) ◽  
pp. 1021-1025
Author(s):  
O. I. Volchok ◽  
V. V. Kalinovskii ◽  
I. F. Kislyak ◽  
I. V. Kolodii ◽  
G. E. Storozhilov ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Structural State ◽  
Deformation Stage

The Effect of Structural State on Magnetic and Magnetocaloric Properties of Micro-and Nanocrystalline Gd

2012 ◽  
Vol 190 ◽  
pp. 315-318 ◽  
Author(s):  
S.A. Nikitin ◽  
A.I. Smarzhevskaya ◽  
T.P. Kaminskaya ◽  
A.S. Semisalova ◽  
V.V. Popov ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Magnetic Properties ◽  
Severe Plastic Deformation ◽  
Structural State ◽  
Magnetic Entropy ◽  
Marked Influence ◽  
Magnetocaloric Properties

The effect of micro-and nanocrystalline structural state on magnetic properties and magnetic entropy (ΔSM) of Gd is investigated. The marked influence of severe plastic deformation on ΔSM is demonstrated.

scholarly journals Effect of Temperature of Severe Plastic Deformation on Mechanical Properties of High Entropy Alloy CoCrFeNiMn

2020 ◽  
Keyword(s):  
Plastic Deformation ◽  
Yield Strength ◽  
Severe Plastic Deformation ◽  
Structural State ◽  
Effect Of Temperature ◽  
High Entropy Alloy ◽  
Active Deformation ◽  
High Entropy ◽  
Temperature Range ◽  
Average Grain Size

High entropy alloy (HEA) CoCrFeNiMn was produced by arc melting of the components in high-purity argon atmosphere with consequent multiple homogenization annealing. The disc-shaped samples with diameter 10 mm and thickness of ~ 1 mm were produced from the ingots obtained. These samples were subjected to severe plastic deformation by high pressure torsion (HPT) in Bridgman anvil at a hydrostatic pressure of 6 GPa and at temperature 77 K. Plungers have been rotated for 5 times at a speed of 0.2 rot/min that allows to produce uniform nanocrystalline structural state with average grain size of less than 100 nm. Mechanical tests have been provided under conditions of uniaxial compression of rectangular samples with size 1.3×0.6×0.6 mm3. The samples were cut from the discs after HPT at a distance of 3 mm form disc centre. The analysis of stress-strain curves have been made in the temperature range of 300-4.2 K for the obtained nanostructured state. It was found that yield stress value monotonically increasing from 1.44 GPa to 2.48 GPa while the temperature decrease from 300 K to 4.2 K, which is typical for thermally activated character of plastic deformation. Anomalous decrease in yield strength values in comparison with the same values for nanostructured HEA after HPT at 300 K was established in all the temperature range (300-4.2 K) for the structural state after HPT at 77 K. The conducted analysis have been shown that the observed anomalous behaviour of yield strength during active deformation is conditioned by peculiarities of microsturcture appearing after cryodeformation by HPT at 77 K, in particular by formation of martensite phase with hcp lattice and connected with this decrease in dislocation density. It was shown that peculiarities of microstructure after HPT at 77 K effect considerably not only on strength of the alloy in local areas, i.e. its microhardness value, but also on the acting stresses responsible for the plastic deformation process under conditions of active deformation of nanocrystalline HEA CoCrFeMnNi.

Hysteresis Magnetic Properties of Nd-Ho-Fe-Co-B Alloys after Intense Plastic Deformation

2010 ◽  
Vol 667-669 ◽  
pp. 1065-1070 ◽  
Author(s):  
Irina S. Tereshina ◽  
Evgeniya A. Tereshina ◽  
Gennady S. Burkhanov ◽  
Sergey V. Dobatkin
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
Magnetic Properties ◽  
Severe Plastic Deformation ◽  
Structural State ◽  
Structural Investigation ◽  
Magnetic Hysteresis ◽  
Induction Melting ◽  
X Ray ◽  
Hysteresis Properties

In the present work a study of the influence of structural state on magnetic hysteresis properties of (Nd,Ho)2(Fe0.8Co0.2)14B compound was carried out. Starting alloy was prepared by induction melting in an Ar atmosphere. Nd-Ho-Fe-Co-B alloys with a nanograin structure were obtained by severe plastic deformation (SPD). Electron microscopy and X-ray analysis were used for the structural investigation. The magnetization measurements were performed using a SQUID magnetometer. It is shown that the relatively high values of coercive force are observed in case of achieved nanograin structure in (Nd,Ho)2(Fe0.8Co0.2)14B. The effect of structural state on hysteresis properties of Y2(Fe0.8Co0.2)14B is also investigated.

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.

Deformation Behaviour and Ultrafine Grained Structure Development in Steels with Different Carbon Content Subjected to Severe Plastic Deformation

2007 ◽  
Vol 345-346 ◽  
pp. 45-48 ◽  
Author(s):  
Jozef Zrník ◽  
Sergey V. Dobatkin ◽  
Ondrej Stejskal
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Work Hardening ◽  
Favourable Effect ◽  
Tensile Behaviour ◽  
Dislocation Network ◽  
Strength Increase ◽  
Subgrain Structure ◽  
Low Carbon ◽  
Channel Angle

The article focuses on the results from recent experimental of severe plastic deformation of low carbon (LC) steel and medium carbon (MC) steel performed at increased temperatures. The grain refinement of ferrite respectively ferrite-pearlite structure is described. While LC steel was deformed by ECAP die (ε = 3) with a channel angle φ = 90° the ECAP severe deformation of MC steel was conducted with die channel angle of 120° (ε = 2.6 - 4). The high straining in LC steel resulted in extensively elongated ferrite grains with dense dislocation network and randomly recovered and polygonized structure was observed. The small period of work hardening appeared at tensile deformation. On the other side, the warm ECAP deformation of MC steel in dependence of increased effective strain resulted in more progressive recovery process. In interior of the elongated ferrite grains the subgrain structure prevails with dislocation network. As straining increases the dynamic polygonization and recrystallization became active to form mixture of polygonized subgrain and submicrocrystalline structure. The straining and moderate ECAP temperature caused the cementite lamellae fragmentation and spheroidzation as number of passes increased. The tensile behaviour of the both steels was characterized by strength increase however the absence of strain hardening was found at low carbon steel. The favourable effect of ferrite-pearlite structure modification due straining was reason for extended work hardening period observed at MC steel.

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