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

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.

2010 ◽  
Vol 667-669 ◽  
pp. 943-948 ◽  
Author(s):  
Veronika Polyakova ◽  
Irina P. Semenova ◽  
Ruslan Valiev

This work is devoted to enhancement of strength and ductility of the Ti-6Al-7Nb ELI alloy, which is less harmful from medical point of view for human body in comparison to Ti-6Al-4V. It has been demonstrated that formation of an ultrafine-grained structure in the alloy with the help of equal-channel angular pressing in combination with heat and deformation treatments allows reaching high strength (UTS = 1400 MPa) and sufficient ductility (elongation 10 %).


2012 ◽  
Vol 05 ◽  
pp. 299-306
Author(s):  
TERENCE G. LANGDON

Processing through the application of severe plastic deformation (SPD) provides a very attractive tool for the production of bulk ultrafine-grained materials. These materials typically have grain sizes in the submicrometer or nanometer ranges and they exhibit high strength at ambient temperature and, if the ultrafine grains are reasonably stable at elevated temperatures, they have a potential for use in superplastic forming operations. Several procedures are now available for applying SPD to metal samples but the most promising are Equal-Channel Angular Pressing (ECAP) and High-Pressure Torsion (HPT). This paper examines the basic principles of ECAP and HPT and describes some of the properties that may be achieved using these processing techniques.


2017 ◽  
Vol 743 ◽  
pp. 203-206 ◽  
Author(s):  
Alexander A. Kozulin ◽  
Vladimir A. Krasnoveikin ◽  
Vladimir A. Skripnyak ◽  
Evgeny N. Moskvichev ◽  
Valery E. Rubtsov

This study examines the effect of severe plastic deformation on the physical and mechanical properties of a light structural Al-Mg alloy. Severe plastic deformation has been performed by equal channel angular pressing through a die with an angle of 90° between the channels to produce ultrafine-grained structure in specimens of studied alloy. A complex investigation of the physical and mechanical properties of the processed alloy has been carried out to examine the microstructure and texture, and to measure microhardness, yield stress and ultimate tensile strength. The obtained results demonstrate high efficiency of the chosen treatment method and mode of producing a light ultrafine-grained alloy.


2009 ◽  
Vol 67 ◽  
pp. 53-58
Author(s):  
V. Anil Kumar ◽  
M.K. Karthikeyan ◽  
Rohit Kumar Gupta ◽  
P. Ramkumar ◽  
P.P. Sinha

Severe plastic deformation processes (SPD) are gaining importance as advanced materials processing techniques and hold immense potential in obtaining ultra fine-grained high strength materials. Among the SPD techniques, Equal channel angular pressing (ECAP) has its own merits to produce materials with ultra fine grains in bulk with better mechanical properties. The material deforms with high level of plastic strain inside the channel resulting in grain refinement of the output material with improvement in mechanical properties. A very viable die configuration was conceptualized and die was made with 1200 channel angle. Processing of 25 mm dia. of Al alloy AA2219 at room temperature was successfully carried out and grain refinement was observed. The mechanism of grain refinement has been studied using optical and transmission electron microscopy (TEM). It was observed that low energy dislocation structure (LEDS) forms concurrently with sub-grain structure due to dislocation rearrangements, which provide stability to the evolving sub-grain structure. Dislocation mobility is hindered by the presence of precipitates and / or intermetallic dispersoids present in the matrix and results in presence of dislocations in grain interiors. The pile up of dislocations at intermetallic dispersoids was confirmed from the dark field TEM micrographs. Present paper describes the experimental procedure and followed to attain severe plastic deformation through ECAP. Increase in hardness as well as refinement in the grain size after 5-passes have been discussed in light of extensive optical and TEM. The mechanisms of grain refinement to achieve nano-grained structure and strengthening accrued from the grain refinement through ECAP has been discussed.


2008 ◽  
Vol 584-586 ◽  
pp. 80-85 ◽  
Author(s):  
Georgy I. Raab ◽  
Ruslan Valiev ◽  
Dmitriy Gunderov ◽  
Terry C. Lowe ◽  
Amit Misra ◽  
...  

A new technique of continuous severe plastic deformation (SPD)-processing, i.e. ECAP (equal channel angular pressing)-Conform is applied for the first time to produce long-length rods of commercial purity Ti with ultrafine-grained structure. The paper reports on the results of investigation of the microstructure and mechanical properties of Ti rods processed by ECAPConform and the following wire drawing.


2013 ◽  
Vol 738-739 ◽  
pp. 486-490 ◽  
Author(s):  
Dmitriy Gunderov ◽  
Alexandr Lukyanov ◽  
Egor Prokofiev ◽  
Anna Churakova ◽  
Vladimir Pushin ◽  
...  

The article represents results of influence of different severe plastic deformation (SPD) techniques on TiNi alloys. It is demonstrated that strength and shape memory effect (SME) of TiNi can be significantly enhanced due to formation of ultrafine-grained (UFG) and nanocrystalline (NC) structures by SPD. Influence of equal channel angular pressing (ECAP), high pressure torsion (HPT), multi-step SPD deformations (ECAP plus cold rolling) on structure, mechanical and functional properties of TiNi alloys is considered. There are represented first results of influence of equal channel angular pressure-Conform (ECAP-C) on TiNi alloys, which is a perspective technology for industrial fabrication of UFG metals and alloys.


2012 ◽  
Vol 715-716 ◽  
pp. 994-999 ◽  
Author(s):  
Galina G. Zakharova ◽  
Elena G. Astafurova ◽  
Evgeny V. Naydenkin ◽  
Georgy I. Raab ◽  
Sergey V. Dobatkin

The present work deals with the evolution of mechanical properties and structure of low-carbon Fe-1,12Mn-0,08V-0,07Ti-0,1C (wt.%) steel after severe plastic deformation (SPD) and high-temperature annealing. Steel in initial ferritic-pearlitic state was deformed by equal channel angular pressing (ECAP) at T=200°C and high pressure torsion (HPT) at room temperature. The evolution of ultrafine grained structure and its thermal stability were investigated after annealing at 400-700°C for 1 hour. The results shown that SPD leads to formation of structure with an average size of (sub-) grain of 260 nm after ECAP and 90 nm after HPT. Ultrafine grained structures produced by SPD reveal a high thermal stability up to 500°C after ECAP and 400°C after HPT. At higher annealing temperatures a growth of structural elements and a decrease in microhardness were observed.


2015 ◽  
Vol 813-814 ◽  
pp. 161-165
Author(s):  
M. Sadhasivam ◽  
T. Pravin ◽  
S. Raghuraman

The need for super-plasticity and high strength leads to the development of Severe Plastic Deformation technique. The strength of the material is directly dependent upon the grain size of the material. So, there is a need for producing Ultra-Fine Grain microstructure (UFG). UFG material is the material with very small grain size in the range of sub-micrometre. Application of severe plastic deformation, imparts extremely high strain. Equal channel angular pressing (ECAP) is a severe plastic deformation process in which the metal specimen is pressed through an angular channel of equal cross section. The material is subjected to shear deformation and strain is imparted in the specimen. Geometric parameters such as channel angle and corner angle play a major role in grain refinement. Aluminium (Al) specimens are subjected to undergo severe plastic deformation. Since, the strength of Al is not high, other materials are added in order to enhance its mechanical properties by matrix work hardening. Copper (Cu) along with Al shows increase in its strength and also in hardness. An attempt is made with Aluminium and copper, blended in the ratio 95:5 by weight with the main objective to study the Tensile strength, Hardness and Percentage Elongation properties of the specimen.


2006 ◽  
Vol 503-504 ◽  
pp. 515-520 ◽  
Author(s):  
Igor V. Alexandrov ◽  
V.V. Latysh ◽  
Sun Ig Hong ◽  
S.N. Faizova ◽  
V.M. Polovnikov

The current work presents new results of investigation of properties and structure of nanocrystalline and submicrocrystalline Cu-1%Cr-0.7%Al alloy. Two severe plastic deformation (SPD) techniques were applied to refine the structure: high pressure torsion and equal-channel angular pressing (ECAP). The first technique was applied to conduct preliminary studies of the alloy different thermal treatments as before SPD as well as after it. A new technological thermomechanical technique for processing of bulk billets of Cu-1%Cr-0.7%Al alloy possessing an ultrafine grained structure was developed on the basis of the obtained results. This technique comprises a combination of ECAP and other deformational processes with the thermal treatment. High values of the tensile strength and yield stress - 700 MPa and 16% accordingly – have been obtained as a result of such treatment, whereas these values after conventional treatment consisted 450 MPa and 20% respectively.


2007 ◽  
Vol 124-126 ◽  
pp. 1325-1328
Author(s):  
Dong Hyuk Shin ◽  
Duck Young Hwang ◽  
Jung Yong Ahn ◽  
Kyung Tae Park ◽  
Yong Suk Kim ◽  
...  

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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