scholarly journals Aging Behaviour of Al-Mg-Si Alloys Subjected to Severe Plastic Deformation by ECAP and Cold Asymmetric Rolling

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
S. Farè ◽  
N. Lecis ◽  
M. Vedani
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Isothermal Aging ◽  
Room Temperature ◽  
Coarse Grained ◽  
Peak Shape ◽  
Asymmetric Rolling ◽  
Ultrafine Grained ◽  
Aging Kinetics ◽  
Reduced Intensity

A study was carried out on aging behaviour of a 6082 alloy processed by two different severe plastic deformation techniques: ECAP and asymmetric rolling. Both techniques were able to generate an ultrafine-grained structure in samples processed at room temperature. It was stated that severe straining promotes marked changes in the postdeformation aging kinetics. The peaks of β′′/β′ transition phases were anticipated and of progressively reduced intensity over the coarse grained alloy. A further peak accounting for onset of recrystallization also appeared in the most severely deformed samples. Full consistency in peak shape and position was found when comparing materials processed by ECAP and asymmetric rolling. Isothermal aging treatments performed at 180°C revealed that in the severely deformed samples, aging became so fast that the hardness curves continuously decreased due to overwhelming effects of structure restoration. On the contrary, aging at 130°C offers good opportunities for fully exploiting the precipitate hardening effects in the ultrafine-grained alloy.

Characterizing the Shear Deformation during Asymmetric Rolling

2008 ◽  
Vol 584-586 ◽  
pp. 327-332 ◽  
Author(s):  
Yun Long Chen ◽  
Ai Dang Shan ◽  
Jian Hua Jiang ◽  
Yi Ding
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Shear Deformation ◽  
Room Temperature ◽  
Pure Aluminum ◽  
Asymmetric Rolling ◽  
Metallic Material ◽  
Side Face ◽  
High Reduction ◽  
Very High

Asymmetric rolling has been considered as a possible way to obtain severe plastic deformation (SPD) since it will give an extra shear deformation to the processed materials during rolling. Previous researches have confirmed such a shear deformation. Very recently, the method of inserting-block is used to characterize the shear deformation through direct observation, but when the reduction is more than 70%, the lineation scratched on the side face of internal mark becomes vague and illegible. In order to directly observe the shear deformation of metallic material with large reduction, the internal mark method is employed in this research and asymmetric rolling was performed with pure aluminum and iron at room temperature. In severe plastic deformation, the shear deformation caused by asymmetric rolling was clearly observed and measured through employing internal mark method. Remarkable extra shear deformation during asymmetric rolling was confirmed. Very high equivalent strains were achieved when sheet samples were asymmetrically rolled to high reduction ratio. These strain values fall into the range of SPD.

Influence of Severe Plastic Deformation on Mechanical Properties of an AA5024 Alloy

2016 ◽  
Vol 879 ◽  
pp. 1317-1322 ◽  
Author(s):  
Anna Mogucheva ◽  
Diana Yuzbekova ◽  
Tatiana Lebedkina ◽  
Mikhail Lebyodkin ◽  
Rustam Kaibyshev
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
High Strength ◽  
Coarse Grained ◽  
Type B ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Elongation To Failure ◽  
Dislocation Strengthening

The paper reports on the effect of severe plastic deformation on mechanical properties of an Al-4.57Mg-0.35Mn-0.2Sc-0.09Zr (in wt. pct.) alloy processed by equal channel angular pressing followed by cold rolling (CR). The sheets of the 5024 alloy with coarse grained (CG) structure exhibited a yield stress (YS) near 410 MPa and an ultimate tensile strength (UTS) of 480 MPa, while the YS and UTS of this material with ultrafine-grained (UFG) structure increased to 530 and 560 MPa, respectively. On the other hand, the elongation to failure decreased by a factor of 2 and 4 after CR and CR following ECAP, respectively. It was shown that dislocation strengthening attributed to extensive CR plays a major role in achieving high strength of this alloy. Besides these macroscopic characteristics, jerky flow caused by the Portevin-Le Chatelier (PLC) instability of plastic deformation was examined. The formation of UFG structure results in a transition from mixed type A+B to pure type B PLC serrations. No such effect on the serrations type was observed after CR.

Submicrocrystalline Austenitic Stainless Steel Processed by Cold or Warm High Pressure Torsion

2016 ◽  
Vol 838-839 ◽  
pp. 398-403 ◽  
Author(s):  
Marina Tikhonova ◽  
Nariman Enikeev ◽  
Ruslan Z. Valiev ◽  
Andrey Belyakov ◽  
Rustam Kaibyshev
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Severe Plastic Deformation ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Submicrocrystalline Structure ◽  
Ultrafine Grained ◽  
Different Temperatures

The formation of submicrocrystalline structure during severe plastic deformation and its effect on mechanical properties of an S304H austenitic stainless steel with chemical composition of Fe – 0.1C – 0.12N – 0.1Si – 0.95Mn – 18.4Cr – 7.85Ni – 3.2Cu – 0.5Nb – 0.01P – 0.006S (all in mass%) were studied. The severe plastic deformation was carried out by high pressure torsion (HPT) at two different temperatures, i.e., room temperature or 400°C. HPT at room temperature or 400°C led to the formation of a fully austenitic submicrocrystalline structure. The grain size and strength of the steels with ultrafine-grained structures produced by cold or warm HPT were almost the same. The ultimate tensile strengths were 1950 MPa and 1828 MPa after HPT at room temperature and 400°C, respectively.

Mechanical and Functional Properties of Titanium Alloys Processed by Severe Plastic Deformation

2011 ◽  
Vol 683 ◽  
pp. 137-148 ◽  
Author(s):  
Vladimir V. Stolyarov
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Mechanical Behavior ◽  
Titanium Alloys ◽  
Functional Properties ◽  
Coarse Grained ◽  
Cyclic Loads ◽  
Metallic Materials ◽  
Ultrafine Grained

Systematized literature data related to the study of mechanical and functional properties of ultrafine-grained and nanostructured metallic materials processed by deformation methods are presented. Special attention is given to the mechanical behavior of titanium materials under tension, as well as under impact and cyclic loads. The advantage of the materials under investigation over their coarse-grained analogues is shown.

The Aspects of Practical Application of Ultrafine-Grained Titanium Alloys Produced by Severe Plastic Deformation

2010 ◽  
Vol 667-669 ◽  
pp. 1183-1187 ◽  
Author(s):  
Evgeny V. Naydenkin ◽  
Ilya V. Ratochka ◽  
Galina P. Grabovetskaya
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Titanium Alloys ◽  
Elevated Temperatures ◽  
Acoustic Properties ◽  
Coarse Grained ◽  
Medical Implants ◽  
Ultrafine Grained ◽  
Mechanical And Physical Properties ◽  
Ultrasound System

The mechanical and physical properties of ultrafine-grained titanium alloys produced by severe plastic deformation are considered. It is found that the formation of ultrafine-grained structure in these materials causes a significant enhancement in their mechanical properties at room temperature and in their resistance to hydrogen embrittlement as well as a change in their acoustic properties. Moreover, superplasticity is realized in these materials at less elevated temperatures relative to the respective coarse grained counterparts. It is shown that the above changes in material properties permit optimization of conditions by the production of items from the titanium alloys, e.g. medical implants having the requisite strength and stepped waveguides having long life even in the high power density conditions of an ultrasound system.

scholarly journals Texture and Young's Modulus Anisotropy in Nanostructured Copper

1999 ◽  
Vol 32 (1-4) ◽  
pp. 321-339 ◽  
Author(s):  
I. V. Alexandrov ◽  
V. N. Serebryany ◽  
L. N. Sarvarova ◽  
M. V. Alexandrova ◽  
R. Z. Valiev
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Young’S Modulus ◽  
Crystallographic Texture ◽  
Young's Modulus ◽  
Coarse Grained ◽  
Elastic Behaviour ◽  
Leading Role ◽  
Ultrafine Grained ◽  
Cold Rolling And Annealing

It was shown that in ultrafine-grained nanostructured Cu processed by severe plastic deformation and subjected to cold rolling and annealing, the level and character of Young's modulus anisotropy is significantly different from values corresponding to cold rolled and annealed coarse-grained Cu. The crystallographic texture formation processes are investigated in these states in parallel. The comparative study of the elastic behaviour and crystallographic texture lets us draw conclusions concerning the leading role of not only developing crystallographic texture but a specific defect structure of grain boundaries as well in the formation of unusual elastic properties of ultrafine-grained materials processed by severe plastic deformation.

Stability of Ultrafine-Grained Microstructure in Fcc Metals Processed by Severe Plastic Deformation

2011 ◽  
Vol 465 ◽  
pp. 195-198 ◽  
Author(s):  
Jenő Gubicza ◽  
Nguyen Q. Chinh ◽  
Sergey V. Dobatkin ◽  
E. Khosravi ◽  
Terence G. Langdon
Keyword(s):  
Thermal Stability ◽  
Plastic Deformation ◽  
Dislocation Density ◽  
Severe Plastic Deformation ◽  
Room Temperature ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
High Dislocation Density ◽  
Ultrafine Grained ◽  
The Stability

The thermal stability of ultrafine-grained (UFG) microstructure in face centered cubic metals processed by severe plastic deformation (SPD) was studied. The influence of the SPD procedure on the stability was investigated for Cu samples processed by Equal-Channel Angular Pressing (ECAP), High-Pressure Torsion (HPT), Multi-Directional Forging and Twist Extrusion at room temperature (RT). It is found that HPT results in the lowest thermal stability due to the very high dislocation density. Furthermore, the effect of the low stacking fault energy of Ag on the stability is also investigated. It is revealed that the UFG microstructure produced in Ag by ECAP is recovered and recrystallized during storage at room temperature. The driving force for this unusual recovery and recrystallization is the high dislocation density developed during ECAP due to the high degree of dislocation dissociation caused by the very low stacking fault energy of Ag.

Mechanical Behaviors of Ultrafine Grained Metallic Materials

2007 ◽  
Vol 124-126 ◽  
pp. 1325-1328
Author(s):  
Dong Hyuk Shin ◽  
Duck Young Hwang ◽  
Jung Yong Ahn ◽  
Kyung Tae Park ◽  
Yong Suk Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Coarse Grained ◽  
Metallic Materials ◽  
Room Temperature Ductility ◽  
Ultrafine Grained ◽  
Superior Mechanical Properties ◽  
Ultrafine Grained Materials ◽  
The Relationship

Ultrafine grained materials fabricated by severe plastic deformation exhibit both superior and inferior mechanical properties, as the prominent structural materials, compared to coarse grained counterparts. The superior mechanical properties are ultrahigh strength and exceptional ductility at high temperatures (i.e., superplasticity). The inferior mechanical properties are lack of strain hardenability and room temperature ductility. In this study, the relationship between microstructure and mechanical properties of ultrafine grained materials fabricated by severe plastic deformation is investigated in order to provide insight broadening their future applicability.

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