Processing, Strength and Ductility of Bulk Nanostructured Metals Produced by Sever Plastic Deformation: An Overview

2009 ◽  
Vol 633-634 ◽  
pp. 131-150 ◽  
Author(s):  
A. Mashreghi ◽  
L. Ghalandari ◽  
M. Reihanian ◽  
M.M. Moshksar
Keyword(s):  
Plastic Deformation ◽  
Nanocrystalline Metals ◽  
Nanostructured Metals ◽  
Ultrahigh Strength ◽  
Nano Scale ◽  
Ultrafine Grained ◽  
Structural Applications ◽  
Sever Plastic Deformation ◽  
Processing Techniques ◽  
Strength And Ductility

Nanostructured metals which have nano-scale microstructure are classified into ultrafine grained metals and nanocrystalline metals. In recent years, many processing techniques have been developed for producing nanostructured metals. Nanostructured metals possess ultrahigh strength but the low ductility is an important limitation on development of these materials for structural applications. This paper overviews various methods of producing nanostructured metals and recent investigations of strength and ductility of nanostructured metals processed by sever plastic deformation.

Unique Mechanical Properties of Nanostructured Metals

2007 ◽  
Vol 7 (11) ◽  
pp. 3765-3770 ◽  
Author(s):  
Nobuhiro Tsuji
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Equivalent Strain ◽  
Coarse Grained ◽  
Roll Bonding ◽  
Nanostructured Metals ◽  
Ultrafine Grained ◽  
Nanocrystalline Structures ◽  
Rolling Deformation

Recently, it becomes possible to fabricate bulk metals having ultrafine grained or nanocrystalline structures of which grain size is in nano-meter dimensions. One of the promising ways to realize bulk nanostructured metals is severe plastic deformation (SPD) above logarithmic equivalent strain of 4. We have developed an original SPD process, named Accumulative Roll Bonding (ARB) using rolling deformation in principle, and have succeeded in fabricating bulk nanostructured sheets of various kinds of metals and alloys. The ARB process and the nanostructured metals fabricated by the ARB are introduced in this paper. The nanostructured metals sometimes perform quite unique mechanical properties, that is rather surprising compared with conventionally coarse grained materials. The unique properties seem to be attributed to the characteristic structures of the nano-metals full of grain boundaries.

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.

High ductility of ultrafine-grained steel via phase transformation

2008 ◽  
Vol 23 (6) ◽  
pp. 1578-1586 ◽  
Author(s):  
S. Cheng ◽  
H. Choo ◽  
Y.H. Zhao ◽  
X-L. Wang ◽  
Y.T. Zhu ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Tensile Ductility ◽  
High Strength ◽  
Strain Rate Effect ◽  
Inhomogeneous Deformation ◽  
Ultrafine Grained ◽  
Structural Applications ◽  
Order Of Magnitude ◽  
Strength And Ductility ◽  
Ultrafine Grained Steel

There is often a tradeoff between strength and ductility, and the low ductility of ultrafine-grained (UFG) materials has been a major obstacle to their practical structural applications despite their high strength. In this study, we have achieved a ∼40% tensile ductility while increasing the yield strength of FeCrNiMn steel by an order of magnitude via grain refinement and deformation-induced martensitic phase transformation. The strain-rate effect on the inhomogeneous deformation behavior and phase transformation was studied in detail.

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 %).

Mössbauer Spectroscopy Studies of Grain Boundaries in Nanostructured Metals

2008 ◽  
Vol 273-276 ◽  
pp. 506-513 ◽  
Author(s):  
Vladimir V. Popov
Keyword(s):  
Mass Transfer ◽  
Plastic Deformation ◽  
Mössbauer Spectroscopy ◽  
Severe Plastic Deformation ◽  
Grain Boundaries ◽  
Mossbauer Spectroscopy ◽  
Nanocrystalline Metals ◽  
Nanostructured Metals ◽  
Mößbauer Spectroscopy ◽  
Spectroscopy Studies

The results of NGR studies of grain boundaries in nanocrystalline metals are briefly reviewed and analyzed together with the data of ordinary diffusion experiments. Grain boundaries in materials obtained both by powder technologies and severe plastic deformation (SPD) are considered. Possible factors causing accelerated mass transfer in every case are analyzed with the account taken of specific features of the structure of these materials.

Unique Mechanical Properties of Nanostructured Metals

2007 ◽  
Vol 7 (11) ◽  
pp. 3765-3770 ◽  
Author(s):  
Nobuhiro Tsuji
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Equivalent Strain ◽  
Coarse Grained ◽  
Roll Bonding ◽  
Nanostructured Metals ◽  
Ultrafine Grained ◽  
Nanocrystalline Structures ◽  
Rolling Deformation

Recently, it becomes possible to fabricate bulk metals having ultrafine grained or nanocrystalline structures of which grain size is in nano-meter dimensions. One of the promising ways to realize bulk nanostructured metals is severe plastic deformation (SPD) above logarithmic equivalent strain of 4. We have developed an original SPD process, named Accumulative Roll Bonding (ARB) using rolling deformation in principle, and have succeeded in fabricating bulk nanostructured sheets of various kinds of metals and alloys. The ARB process and the nanostructured metals fabricated by the ARB are introduced in this paper. The nanostructured metals sometimes perform quite unique mechanical properties, that is rather surprising compared with conventionally coarse grained materials. The unique properties seem to be attributed to the characteristic structures of the nano-metals full of grain boundaries.

Processing, Characteristics And Applications Of Bulk Nanostructured Metals And Alloys

2021 ◽  
Vol 06 ◽  
Author(s):  
T. S. Srivatsan ◽  
K. Manigandan
Keyword(s):  
Plastic Deformation ◽  
Nanostructured Materials ◽  
Materials Science ◽  
High Pressure Torsion ◽  
Structural Materials ◽  
Metals And Alloys ◽  
Surface Mechanical Attrition Treatment ◽  
Computational Techniques ◽  
Nanostructured Metals ◽  
Structural Applications

: An ability to achieve useful properties in structural materials is largely dependent on their bulk microstructure. Over the years, the innate ability to achieve noticeable improvements in structural materials has relied upon processing as a viable means and/or alternative, which in turn determines the resulting microstructure and properties or behavior. Sustained research and development efforts in the domains encompassing materials science, materials engineering and manufacturing processes has made possible the arrival of a time period in which specific properties of a material can be obtained by carefully controlling the architecture of its constituents. Nanostructuring of materials to include both metals and their alloy counterparts is a key for obtaining extra ordinary properties that made them attractive for purpose of selection and use in both structural applications and functional applications. In recent years, the production of bulk nanostructured materials [BNMs] by techniques of severe plastic deformation [SPD] has attracted considerable scientific and technological interest since it offers new opportunities for the fabrication of commercial nanostructured metals and alloys that can be chosen for use in a variety of specific applications. Such nanostructured materials must essentially be not only porosity free and but also contaminant free, which makes them an ideal choice for studying, observing and documenting their characteristics spanning microstructure, properties and mechanical behavior. In this paper, we provide a compelling overview of the approaches most widely used for the purpose of achieving grain refinement using the technique of plastic deformation. An outline of the four most commonly used plastic deformation processing techniques is provided. Salient aspects specific to the technique of equal channel angular pressing [ECAP], high pressure torsion [HPT], accumulative roll bonding [ARB] of bulk nanostructured metals and surface mechanical attrition treatment [SMAT] of nanostructured layers is provided and briefly discussed. A need for the selection of certain metals and alloys for use in specific applications in the domains spanning medicine and technology are briefly discussed. The emergence and use of computational nanotechnology, which in essence synergizes the rapid developments in computational techniques and material development is presented and briefly discussed.

Enhanced Strength and Ductility of Ultrafine-Grained Ti Processed by Severe Plastic Deformation

2010 ◽  
Vol 12 (8) ◽  
pp. 803-807 ◽  
Author(s):  
Irina Semenova ◽  
Gulnaz Salimgareeva ◽  
Gérald Da Costa ◽  
Williams Lefebvre ◽  
Ruslan Valiev
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Ultrafine Grained ◽  
Strength And Ductility

Crystallographic Features of Martensite Transformed from Ultrafine Grained Austenite Fabricated by Severe Plastic Deformation

2012 ◽  
Vol 706-709 ◽  
pp. 1835-1840
Author(s):  
Akinobu Shibata ◽  
Hamidreza Jafarian ◽  
Daisuke Terada ◽  
Nobuhiro Tsuji
Keyword(s):  
Plastic Deformation ◽  
Orientation Relationship ◽  
Large Deviation ◽  
Martensite Plate ◽  
High Density ◽  
Coarse Grained ◽  
Density Of Dislocations ◽  
Austenite Grain ◽  
Ultrafine Grained ◽  
Sever Plastic Deformation

We studied the crystallographic features, especially the orientation relationship with respect to austenite, of martensite in a steel transformed from coarse-grained equiaxed austenite (35 μm), ultrafine-grained equiaxed (2.5 μm) or lamellar (300nm) austenite fabricated by sever plastic deformation. With decreasing the grain size of equiaxed austenite, the orientation relationship changed from Kurdjumov - Sachs relationship to Greninger - Troiano relationship. We inferred that this change of orientation relationship could be attributed to the small size of martensite plate transformed from the ultrafine-grained equiaxed austenite. The martensite transformed from the ultrafine-grained lamellar austenite did not have a definite orientation relationship with austenite. We considered that a high density of dislocations or a high density of low angle boundaries within the ultrafine lamellar austenite grain resulted in the large deviation of orientation relationship.

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