Structure and Thermal Stability of Cu after Severe Plastic Deformation

2010 ◽  
Vol 297-301 ◽  
pp. 1312-1321 ◽  
Author(s):  
Vladimir V. Popov ◽  
A.V. Stolbovkiy ◽  
E.N. Popova ◽  
V.P. Pilyugin
Keyword(s):  
Thermal Stability ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
High Pressure Torsion ◽  
Pure Copper ◽  
Nanocrystalline Structure ◽  
Transmission Electron ◽  
Evolution Of Structure ◽  
Stability Of Structure ◽  
Thermal Stability Of

Evolution of structure of high-purity and commercially pure copper at severe plastic deformation (SPD) by high pressure torsion (HPT) at room temperature and in liquid nitrogen has been studied by transmission electron microscopy (TEM) and measurements of microhardness. Thermal stability of structure obtained by HPT has been investigated. Factors preventing from obtaining nanocrystalline structure in Cu are analyzed and possible ways of their overcoming are discussed.

The Structure of Nb Obtained by Severe Plastic Deformation and its Thermal Stability

2010 ◽  
Vol 667-669 ◽  
pp. 409-414 ◽  
Author(s):  
Vladimir V. Popov ◽  
E.N. Popova ◽  
A.V. Stolbovsky ◽  
V.P. Pilyugin
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Transmission Electron Microscopy ◽  
Plastic Deformation ◽  
High Pressure Torsion ◽  
Nanocrystalline Structure ◽  
Transmission Electron ◽  
Crystallite Sizes ◽  
Evolution Of Structure ◽  
Thermal Stability Of

Evolution of structure of Nb subjected to high-pressure torsion (HPT) with various strain at cryogenic and room temperatures and further annealing in the temperature range of 100-7000C has been studied by transmission electron microscopy (TEM) and microhardness measurements. HPT in liquid nitrogen enables to obtain true nanocrystalline structure with crystallite sizes of about 75 nm and the record-breaking microhardness of 4800 MPa. The thermal stability of the structure obtained is analysed.

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.

Influence of Temperature of Severe Plastic Deformation and Aging on Microstructure, Mechanical Properties and Electrical Conductivitiy of the Cu-Cr-Zr Alloy

2018 ◽  
Vol 385 ◽  
pp. 273-277
Author(s):  
Elena Sarkeeva ◽  
Marina M. Abramova ◽  
Igor V. Alexandrov
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Influence Of Temperature ◽  
Annealed Copper ◽  
Thermal Stability Of ◽  
Zr Alloy

The article studies an influence of temperature of severe plastic deformation (SPD) and post-deformation heat treatment on microstructure, mechanical properties and thermal stability of the Cu-0.5Cr-0.2Zr alloy. The results demonstrate that strength is considerably increased to 900 MPa by high pressure torsion (HPT) at room temperature. Subsequent ageing at 450 °С during 1 hour leads to a decay of solid solution and an allocation of dispersion particles that further incrises strength to 900 MPa, restores electrical conductivity to 70% IACS (International annealed copper standard) and enhances thermal stability of the alloy. When deformation temperature is increased to 300°С, strength is 690 MPa that is lower than in the case of deformation at room temperature that is related to reversion process at deformation. Additional a aging does not lead to an increase of strength characteristics.

Evolution of Structure and Phase Composition of Aluminum Alloy under Severe Plastic Deformation

2014 ◽  
Vol 880 ◽  
pp. 179-183
Author(s):  
Evgeniy V. Naydenkin ◽  
Konstantin V. Ivanov ◽  
Gennadiy E. Rudenskii
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Plastic Deformation ◽  
Aluminum Alloy ◽  
Severe Plastic Deformation ◽  
S Phase ◽  
High Thermal Stability ◽  
Ultrafine Grained ◽  
Evolution Of Structure ◽  
Thermal Stability Of

The paper shows that high thermal stability of the ultrafine-grained structure of aluminum alloy produced by severe plastic deformation is related to S-phase particles. The sequence of phase transformations of zirconium-doped ultrafine-grained alloy Al-Mg-Li in heating is revealed. The paper also determines temperatures at which depending on crystal structure two types of S-phase particles can form.

Structure, Thermal Stability and Properties of Grain Boundaries of Submicrocrystalline Mo Obtained by Severe Plastic Deformation

2012 ◽  
Vol 326-328 ◽  
pp. 674-681 ◽  
Author(s):  
Vladimir V. Popov ◽  
Galina P. Grabovetskaya ◽  
A.V. Sergeev ◽  
I.P. Mishin
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Transmission Electron Microscopy ◽  
Plastic Deformation ◽  
High Pressure ◽  
Severe Plastic Deformation ◽  
Grain Boundaries ◽  
High Pressure Torsion ◽  
Emission Mössbauer Spectroscopy ◽  
Transmission Electron

The structure of submicrocrystalline Mo, obtained by high pressure torsion, its thermal stability and the state of grain boundaries have been studied by transmission electron microscopy and emission Mössbauer spectroscopy.

TEM Study of Local Disordering: A Structural Phase Change Induced by High-Pressure Torsion

2008 ◽  
Vol 584-586 ◽  
pp. 422-427 ◽  
Author(s):  
Christian Rentenberger ◽  
Clemens Mangler ◽  
Stephan Scheriau ◽  
Reinhard Pippan ◽  
Hans Peter Karnthaler
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
Severe Plastic Deformation ◽  
High Pressure Torsion ◽  
Structural Phase ◽  
Nanocrystalline Structure ◽  
Coarse Grained ◽  
Intermetallic Alloys ◽  
Transmission Electron ◽  
Ordered Intermetallic

Long-range ordered intermetallic alloys with L12 (Ni3Al, Cu3Au) and B2 (FeAl) structures were deformed by high-pressure torsion at room temperature up to high grades of deformation. Transmission electron microscopy shows that disordering caused by the deformation occurs on a very local scale within coarse grains along glide planes (Cu3Au, Ni3Al) and in the form of well defined local regions (Ni3Al, FeAl). The latter leads to a duplex structure consisting of an ordered coarse-grained structure and a disordered nanocrystalline structure. The different mechanisms that can lead to disordering during severe plastic deformation are discussed on the basis of the different ordering energies and on the basis of antiphase boundaries associated with gliding dislocations. The results indicate that in intermetallic alloys the formation of a nanocrystalline structure by severe plastic deformation is facilitated by the loss of order.

Effect of Ultrasonic Treatment on the Microstructure and Properties of Nanostructured Nickel Processed by High Pressure Torsion

2010 ◽  
Vol 667-669 ◽  
pp. 605-609 ◽  
Author(s):  
Asiya Nazarova ◽  
Radik R. Mulyukov ◽  
Yuriy Tsarenko ◽  
Vasiliy Rubanik ◽  
Ayrat A. Nazarov
Keyword(s):  
Thermal Stability ◽  
Plastic Deformation ◽  
High Pressure ◽  
Severe Plastic Deformation ◽  
Grain Growth ◽  
Ultrasonic Treatment ◽  
High Pressure Torsion ◽  
Pure Nickel ◽  
Internal Stresses ◽  
Thermal Stability Of

The effect of ultrasonic treatment on the microstructure, microhardness and thermal stability of pure nickel after high pressure torsion (HPT) was studied. It was shown that the ultrasonic treatment reduces internal stresses induced by severe plastic deformation. The higher the intensity of ultrasound in the range studied, the stronger is this effect. Also it was revealed that grain growth in nickel processed by HPT followed by ultrasonic treatment occurs at higher temperatures than that in nickel as-processed by HPT, i.e. the thermal stability of nanostructured nickel is increased.

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.

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