scholarly journals On the origin of the extremely high strength of ultrafine-grained Al alloys produced by severe plastic deformation

2010 ◽  
Vol 63 (9) ◽  
pp. 949-952 ◽  
Author(s):  
R.Z. Valiev ◽  
N.A. Enikeev ◽  
M.Yu. Murashkin ◽  
V.U. Kazykhanov ◽  
X. Sauvage
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
High Strength ◽  
Al Alloys ◽  
Ultrafine Grained

scholarly journals Potential of High Compressive Ductility of Ultrafine Grained Copper Fabricated by Severe Plastic Deformation

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1503
Author(s):  
Mayu Asano ◽  
Motohiro Yuasa ◽  
Hiroyuki Miyamoto ◽  
Tatsuya Tanaka ◽  
Can Erdogan ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Void Formation ◽  
Rate Sensitivity ◽  
High Strength ◽  
Local Strain ◽  
Tensile Tests ◽  
Dislocation Slip ◽  
Shear Mode ◽  
Ultrafine Grained

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.

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

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.

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.

Severe Plastic Deformation under High Pressure for Production of Superplastic Materials

2016 ◽  
Vol 838-839 ◽  
pp. 287-293 ◽  
Author(s):  
Zenji Horita
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
High Pressure ◽  
Severe Plastic Deformation ◽  
Grain Refinement ◽  
High Pressure Torsion ◽  
High Strength ◽  
Al Alloys ◽  
Strain Rates ◽  
Ti Alloys

Grain refinement is an important prerequisite for advent of superplasticity. In particular, as the grain size is smaller, the superplasticity appears at higher strain rates and lower temperatures. Severe plastic deformation (SPD) is a useful process for achieving significant grain refinement. This presentation shows that applicability of the SPD process is enhanced when it is operated under high pressure through high-pressure torsion (HPT) and high-pressure sliding (HPS). It is demonstrated that commercially available conventional alloys but less ductile alloys such as Mg alloys, age-hardenable high-strength Al alloys (A2024, A7075) and Ti alloys become superplastic after processing by HPT or HPS.

scholarly journals Precipitation Behaviors from Ultrafine Grained Al Alloys Fabricated by Severe Plastic Deformation

Materia Japan ◽  
2010 ◽  
Vol 49 (7) ◽  
pp. 305-306 ◽  
Author(s):  
Nobuhiro Tsuji ◽  
Daisuke Terada ◽  
Keiyu Nakagawa ◽  
Teruto Kanadani
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Al Alloys ◽  
Ultrafine Grained

Influence of Annealing on the Structure and Mechanical Properties of Ultrafine-Grained Alloy Ti-6Al-7Nb, Processed by Severe Plastic Deformation

2010 ◽  
Vol 667-669 ◽  
pp. 943-948 ◽  
Author(s):  
Veronika Polyakova ◽  
Irina P. Semenova ◽  
Ruslan Valiev
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Equal Channel Angular Pressing ◽  
Human Body ◽  
High Strength ◽  
Point Of View ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Strength And Ductility

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 %).

Deformation Mechanisms and Ductility of Nanostructured Al Alloys

2004 ◽  
Vol 821 ◽  
Author(s):  
Bing Q. Han ◽  
Farghalli A. Mohamed ◽  
Enrique J. Lavernia
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Aluminum Alloys ◽  
Severe Plastic Deformation ◽  
Work Hardening ◽  
Tensile Ductility ◽  
High Strength ◽  
Al Alloys ◽  
Deformation Mechanisms ◽  
Coarse Grains

AbstractLow tensile ductility is one of the critical challenges facing the science and technology of nanostructured materials. As an example, despite the fact that high strength is frequently observed in bulk nanostructured Al alloys, ductility and work hardening are often observed to decrease with decreasing grain size. In the present study, the tensile ductility of bulk nanostructured aluminum alloys processed via severe plastic deformation and consolidation of mechanically milled powders is analyzed. Adding coarse grains to the nanostructured matrix is proposed as an approach to improve ductility.

scholarly journals Ultrafine-Grained High Strength Cu-Ni-Si Alloys

2017 ◽  
Vol 892 ◽  
pp. 64-69 ◽  
Author(s):  
Igor Altenberger ◽  
Hans Achim Kuhn ◽  
Mozhgan Gholami-Kermanshahi ◽  
Mansour Mhaede ◽  
Manfred Wollmann ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Copper Alloys ◽  
Pure Copper ◽  
High Strength ◽  
Solid Solution Hardening ◽  
Subsequent Aging ◽  
Ultrafine Grained ◽  
Wide Range

Ultrafine-grained (UFG) pure copper has been in the focus of materials scientists over the last two decades, however ultrafine-grained high-strength copper alloys have scarcely been processed or characterized so far industrially.In this contribution, UFG copper alloys, especially Cu-Ni-Si alloys, being well known as ideal materials for electromechanical connectors, springs and leadframes, are presented. Precipitation hardened Cu-Ni-Si alloys are a well established and technologically important class of materials for a wide range of applications where high strength and good conductivity are required. Yield strength and fatigue properties of metallic alloys can be significantly enhanced by severe plastic deformation methods. In contrast to other strengthening methods such as solid solution hardening, severe plastic deformation leads to a weaker decrease of electrical conductivity and is therefore a means of enhancing strength while maintaining acceptable conductivity for current bearing parts and components. Characterization of these materials after severe plastic deformation by swaging, wire drawing and subsequent aging was carried out using conductivity-, hardness-and tensile tests as well as highly-resolved microstructural characterization methods.The results reveal that UFG low alloyed copper alloys exhibit impressive combinations of properties such as strength, conductivity, high ductility as well as acceptable thermal stability at low and medium temperatures. By a subsequent aging treatment the severely plastically deformed microstructure of Cu-Ni-Si alloys can be further enhanced and thermal stability can profit from grain-boundary pinning by precipitated nanoscale nickel silicides.

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