Structure and Properties of Mg-Al-Ca Alloy after Severe Plastic Deformation

2008 ◽  
Vol 584-586 ◽  
pp. 559-564 ◽  
Author(s):  
Sergey V. Dobatkin ◽  
Yuri Estrin ◽  
L.L. Rokhlin ◽  
Mikhail V. Popov ◽  
Rimma Lapovok ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Severe Plastic Deformation ◽  
High Pressure Torsion ◽  
Nanocrystalline Structure ◽  
Grain Structure ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Different Types ◽  
Lower Temperature

Severe plastic deformation of a Mg-Al-Ca alloy resulted in different types of grain structure. High pressure torsion (HPT) was shown to lead to the formation of a nanocrystalline structure with a grain size of 100-200 nm, while equal channel angular pressing (ECAP) produced ultrafine grained (UFG) or submicrocrystalline (SMC) structures, depending on the ECAP temperature. An UFG structure with a grain size of 2-5 -m was formed at 300°C, as distinct from a finer SMC structure with a grain size of 300-800 nm formed at a lower temperature (220°C). The possibility of increasing the strength of the alloy in the UFG condition by a factor of 1.5-2, combined with a reasonable level of ductility and enhanced functional properties was thus demonstrated. ECAP of annealed Mg-Al-Ca with the formation of UFG structure was shown to lead to increased yield strength (by a factor of 2) and enhanced tensile ductility (by a factor of 3).

Role of Strain Gradient and Dynamic Transformation on the Formation of Nanocrystalline Structure Produced by Severe Plastic Deformation

2007 ◽  
Vol 539-543 ◽  
pp. 2787-2792 ◽  
Author(s):  
Minoru Umemoto ◽  
Yoshikazu Todaka ◽  
Jin Guo Li ◽  
Koichi Tsuchiya
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Grain Refinement ◽  
Strain Gradient ◽  
High Pressure Torsion ◽  
Large Strain ◽  
Nanocrystalline Structure ◽  
Angular Pressing ◽  
Dynamic Transformation ◽  
Fine Grained Structure

Formation of nanocrystalline structure by severe plastic deformation has studied extensively. Although ultra fine grained structure (grain size larger than 100 nm) had been obtained in many processes such as heavy cold rolling, equal channel angular pressing (ECAP) or accumulative roll bonding (ARB), the formation of nano grained structure (< 100 nm) is limited to processes such as ball milling, shot peening or drilling. In the present study, high pressure torsion (HPT) deformation and drilling were carried out to understand the conditions necessary to obtain nano grained structure in steels. The results of HPT experiments in pure Fe showed that HPT has superior ability of strengthening and grain refinement probably due to a strain gradient but the saturation of grain refinement occurs before reaching nano grained structure. Drilling experiments in high carbon martensitic steel revelaed that nano grained ferrite forms at the drilled hole surface only when the transformation from ferrite to austenite takes place during drilling. Considering various other processes by which nano grained ferrite was produced, it is proposed that heavy strains with large strain gradients together with dynamic transformation are necessary to reach nano grained ferrite structure.

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.

Microstructure and Mechanical Properties of the SPD-Processed TiNi Alloys

2013 ◽  
Vol 738-739 ◽  
pp. 486-490 ◽  
Author(s):  
Dmitriy Gunderov ◽  
Alexandr Lukyanov ◽  
Egor Prokofiev ◽  
Anna Churakova ◽  
Vladimir Pushin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
High Pressure ◽  
Severe Plastic Deformation ◽  
Cold Rolling ◽  
High Pressure Torsion ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
First Results ◽  
Equal Channel Angular Pressure

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.

The Evolution of Structure and Mechanical Properties of Fe-Mn-V-Ti-0,1C Low-Carbon Steel Subjected to Severe Plastic Deformation and Subsequent Annealing

2012 ◽  
Vol 715-716 ◽  
pp. 994-999 ◽  
Author(s):  
Galina G. Zakharova ◽  
Elena G. Astafurova ◽  
Evgeny V. Naydenkin ◽  
Georgy I. Raab ◽  
Sergey V. Dobatkin
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
High Pressure Torsion ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Average Size

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.

Nanostructuring of Ni by Various Modes of Severe Plastic Deformation

2014 ◽  
Vol 354 ◽  
pp. 109-119 ◽  
Author(s):  
Vladimir V. Popov ◽  
E.N. Popova ◽  
D.D. Kuznetsov ◽  
A.V. Stolbovsky ◽  
E.V. Shorohov ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Cryogenic Temperature ◽  
High Pressure Torsion ◽  
Nanocrystalline Structure ◽  
Deformation Bands ◽  
Angular Pressing ◽  
Dynamic Channel Angular Pressing ◽  
Thermal Stability Of

Various modes of severe plastic deformation (SPD), such as high-pressure torsion (HPT) at cryogenic temperature, equal channel angular pressing (ECAP) and dynamic channel-angular pressing (DCAP), have been applied for nanostructuring of Ni, and the thermal stability of the structure obtained has been studied. The nanocrystalline structure with average grain sizes of 80 nm and the microhardness of 6200 MPa is produced by HPT in liquid nitrogen. DCAP and ECAP result in the submicrocrystalline structure of a mixed type, with ultra-fine grains separated by high-angle boundaries along with deformation bands and coarse cells with low-angle dislocation boundaries. The thermal stability of the structures obtained by ECAP and DCAP is approximately the same, and it is higher than after the HPT at cryogenic temperature.

Development of Complex Methods, Combining Thermal Treatment with Severe Plastic Deformation, for Processing of High-Strength Nanostructured Cu-1%Cr-0.7%Al Alloy

2006 ◽  
Vol 503-504 ◽  
pp. 515-520 ◽  
Author(s):  
Igor V. Alexandrov ◽  
V.V. Latysh ◽  
Sun Ig Hong ◽  
S.N. Faizova ◽  
V.M. Polovnikov
Keyword(s):  
Plastic Deformation ◽  
Thermal Treatment ◽  
Severe Plastic Deformation ◽  
High Pressure Torsion ◽  
High Strength ◽  
Al Alloy ◽  
Thermal Treatments ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Complex Methods

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.

The Evolution of Structure and Mechanical Properties of Fe-Mn-V-Ti-0,1C Low-Carbon Steel Subjected to Severe Plastic Deformation and Subsequent Annealing

2010 ◽  
Vol 667-669 ◽  
pp. 325-330 ◽  
Author(s):  
Galina G. Zakharova ◽  
Elena G. Astafurova ◽  
Evgeny V. Naydenkin ◽  
Georgy I. Raab ◽  
Sergey V. Dobatkin
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
High Pressure Torsion ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Average Size

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.

Ultrafine Grained Low Carbon Steels Processed by Severe Plastic Deformation

2008 ◽  
Vol 584-586 ◽  
pp. 623-630 ◽  
Author(s):  
Sergey V. Dobatkin ◽  
P.D. Odessky ◽  
Svetlana V. Shagalina
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Severe Plastic Deformation ◽  
High Pressure Torsion ◽  
High Strength ◽  
Carbon Steels ◽  
Low Alloy Steels ◽  
Low Carbon ◽  
Low Carbon Steels ◽  
Ultrafine Grained

The structure, mechanical and functional properties of ultrafine-grained low-carbon steels have been studied after severe plastic deformation (SPD) by high pressure torsion (HPT) and equalchannel angular pressing (ECAP). It is revealed that HPT of low carbon steels at a temperature below 0.3 Tm leads to the formation of nanocrystalline structure with a grain size of <100 nm or a mixture of oriented substructure and nanograins. ECAP under similar conditions leads to the formation of submicrocrystalline structure with a grain size of 200-300 nm. The initial martensitic state compared with the initial ferritic-pearlitic state of the low-carbon steels results in formation of finer structure after SPD and less intense grain growth upon heating, i.e., results in a higher thermal stability. Low-carbon low-alloy steels after ECAP are characterized by high strength (UTS > 1000 MPa) and plasticity (EL = 10-15%). The high-strength state after ECAP is retained upon tensile test testing up to a temperature of 500°C. The submicrocrystalline low-carbon steels after ECAP processing and subsequent heating is characterized by an increased impact toughness at test temperatures down to -40°C.

Investigations on Microstructure Evolution and Deformation Behavior of Aged and Ultrafine Grained Al-Zn-Mg Alloy Subjected to Severe Plastic Deformation

2010 ◽  
Vol 667-669 ◽  
pp. 253-258
Author(s):  
Wei Ping Hu ◽  
Si Yuan Zhang ◽  
Xiao Yu He ◽  
Zhen Yang Liu ◽  
Rolf Berghammer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Severe Plastic Deformation ◽  
Microstructure Evolution ◽  
Deformation Behavior ◽  
Deformation Mechanisms ◽  
Mg Alloy ◽  
Ultrafine Grained

An aged Al-5Zn-1.6Mg alloy with fine η' precipitates was grain refined to ~100 nm grain size by severe plastic deformation (SPD). Microstructure evolution during SPD and mechanical behaviour after SPD of the alloy were characterized by electron microscopy and tensile, compression as well as nanoindentation tests. The influence of η' precipitates on microstructure and mechanical properties of ultrafine grained Al-Zn-Mg alloy is discussed with respect to their effect on dislocation configurations and deformation mechanisms during processing of the alloy.

MULTI-SCALE FINITE ELEMENT SIMULATION OF SEVERE PLASTIC DEFORMATION

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1621-1626
Author(s):  
HYOUNG SEOP KIM
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Severe Plastic Deformation ◽  
Constitutive Model ◽  
Dislocation Cell ◽  
Ultrafine Grain ◽  
Angular Pressing ◽  
Element Simulation ◽  
Ultrafine Grain Size ◽  
Ultrafine Grained

The technique of severe plastic deformation (SPD) enables one to produce metals and alloys with an ultrafine grain size of about 100 nm and less. As the mechanical properties of such ultrafine grained materials are governed by the plastic deformation during the SPD process, the understanding of the stress and strain development in a workpiece is very important for optimizing the SPD process design and for microstructural control. The objectives of this work is to present a constitutive model based on the dislocation density and dislocation cell evolution for large plastic strains as applied to equal channel angular pressing (ECAP). This paper briefly introduces the constitutive model and presents the results obtained with this model for ECAP by the finite element method.

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