Microstructure tailoring of Al0.5CoCrFeMnNi to achieve high strength and high uniform strain using severe plastic deformation and an annealing treatment

Severe plastic deformation (SPD) can fabricate high-strength materials by forming an ultrafine grained (UFG) microstructure. Low elongation to failure of UFG materials in tensile tests, which has often been regarded as a measure of ductility of materials, has been attributed to low strain hardening of UFG structures where dislocation slip and its accumulation is very limited. In the present work, it is shown that the compressive extensibility of UFG materials can be comparable or potentially superior to that of annealed materials by using a parallel round-bar compression (PRBC) test which was designed for imposing an appropriate stress state preferable for high ductility using the shear mode. The high compressive extensibility of UFG materials can be a result of high accommodation of local strain incompatibility at non-equilibrium grain boundaries and a grain boundary-mediated deformation mechanism, which result in high damage tolerance against void formation and growth. Low strain rate sensitivity indicated that the superplastic viscous nature of deformation is not involved in the high compressive ductility of UFG materials using SPD.

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High strength and good electrical conductivity in Cu–Cr alloys processed by severe plastic deformation

Materials Letters ◽

10.1016/j.matlet.2015.03.144 ◽

2015 ◽

Vol 153 ◽

pp. 5-9 ◽

Cited By ~ 56

Author(s):

S.V. Dobatkin ◽

J. Gubicza ◽

D.V. Shangina ◽

N.R. Bochvar ◽

N.Y. Tabachkova

Keyword(s):

Electrical Conductivity ◽

Plastic Deformation ◽

Severe Plastic Deformation ◽

High Strength

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Processing of Aluminium Alloys by Severe Plastic Deformation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.519-521.45 ◽

2006 ◽

Vol 519-521 ◽

pp. 45-54 ◽

Cited By ~ 2

Author(s):

Terence G. Langdon

Keyword(s):

Plastic Deformation ◽

High Pressure ◽

Severe Plastic Deformation ◽

Elevated Temperatures ◽

High Pressure Torsion ◽

Simple Procedure ◽

Superplastic Forming ◽

High Strength ◽

Ultrafine Grain ◽

Grain Sizes

Processing through the application of severe plastic deformation (SPD) has become important over the last decade because it is now recognized that it provides a simple procedure for producing fully-dense bulk metals with grain sizes lying typically in the submicrometer range. There are two major procedures for SPD processing. First, equal-channel angular pressing (ECAP) refers to the repetitive pressing of a metal bar or rod through a die where the sample is constrained within a channel bent through an abrupt angle at, or close to, 90 degrees. Second, high-pressure torsion (HPT) refers to the procedure in which the sample, generally in the form of a thin disk, is subjected to a very high pressure and concurrent torsional straining. Both of these processes are capable of producing metallic alloys with ultrafine grain sizes and with a reasonable degree of homogeneity. Furthermore, the samples produced in this way may exhibit exceptional mechanical properties including high strength at ambient temperature through the Hall-Petch relationship and a potential superplastic forming capability at elevated temperatures. This paper reviews these two procedures and gives examples of the properties of aluminum alloys after SPD processing.

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THE PROPERTIES OF BULK ULTRAFINE-GRAINED METALS PROCESSED THROUGH THE APPLICATION OF SEVERE PLASTIC DEFORMATION

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194512002164 ◽

2012 ◽

Vol 05 ◽

pp. 299-306

Author(s):

TERENCE G. LANGDON

Keyword(s):

Plastic Deformation ◽

Severe Plastic Deformation ◽

Elevated Temperatures ◽

High Pressure Torsion ◽

Superplastic Forming ◽

High Strength ◽

Basic Principles ◽

Angular Pressing ◽

Ultrafine Grained ◽

Processing Techniques

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.

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Multiscale two-phase Ti–Al with high strength and plasticity through consolidation of particles by severe plastic deformation

Scripta Materialia ◽

10.1016/j.scriptamat.2011.07.014 ◽

2011 ◽

Vol 65 (8) ◽

pp. 711-714 ◽

Cited By ~ 4

Author(s):

E.W. Lui ◽

W. Xu ◽

X. Wu ◽

K. Xia

Keyword(s):

Plastic Deformation ◽

Severe Plastic Deformation ◽

High Strength ◽

Two Phase ◽

Strength And Plasticity

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.879.1317 ◽

2016 ◽

Vol 879 ◽

pp. 1317-1322 ◽

Cited By ~ 3

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.

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