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

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.

2010 ◽  
Vol 297-301 ◽  
pp. 1312-1321 ◽  
Author(s):  
Vladimir V. Popov ◽  
A.V. Stolbovkiy ◽  
E.N. Popova ◽  
V.P. Pilyugin

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.


2012 ◽  
Vol 715-716 ◽  
pp. 994-999 ◽  
Author(s):  
Galina G. Zakharova ◽  
Elena G. Astafurova ◽  
Evgeny V. Naydenkin ◽  
Georgy I. Raab ◽  
Sergey V. Dobatkin

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.


2014 ◽  
Vol 354 ◽  
pp. 109-119 ◽  
Author(s):  
Vladimir V. Popov ◽  
E.N. Popova ◽  
D.D. Kuznetsov ◽  
A.V. Stolbovsky ◽  
E.V. Shorohov ◽  
...  

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.


2006 ◽  
Vol 503-504 ◽  
pp. 971-976 ◽  
Author(s):  
Alexei Vinogradov ◽  
T. Suzuki ◽  
Satoshi Hashimoto ◽  
Kazuo Kitagawa ◽  
A.A. Kuznetsov ◽  
...  

The present work is aimed at linking the microstuctutral features obtained after severe plastic deformation via ECAP to the tensile behavior and thermal stability of pure (99.98%) copper processed by routes A and Bc to different number of passes. The main conclusion one can draw unambiguously from the currently available results is that the strain path exerts relatively little effect on the resultant tensile properties when the number of pressing is sufficiently large, although there have been some marked differences in crystallographic textures and distribution of grain-boundaries. The effect of the number of pressings on the tensile ductility is considerable.


2010 ◽  
Vol 667-669 ◽  
pp. 325-330 ◽  
Author(s):  
Galina G. Zakharova ◽  
Elena G. Astafurova ◽  
Evgeny V. Naydenkin ◽  
Georgy I. Raab ◽  
Sergey V. Dobatkin

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.


2010 ◽  
Vol 667-669 ◽  
pp. 605-609 ◽  
Author(s):  
Asiya Nazarova ◽  
Radik R. Mulyukov ◽  
Yuriy Tsarenko ◽  
Vasiliy Rubanik ◽  
Ayrat A. Nazarov

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.


2018 ◽  
Vol 385 ◽  
pp. 39-44 ◽  
Author(s):  
Fernando Carreño ◽  
Oscar A. Ruano

The 7075 (Al-Zn-Mg-Cu) aluminium alloy is the reference alloy for aerospace applications due to its specific mechanical properties at room temperature, showing excellent tensile strength and sufficient ductility. Formability at high temperature can be improved by obtaining superplasticity as a result of fine, equiaxed and highly misoriented grains prone to deform by grain boundary sliding (GBS). Different severe plastic deformation (SPD) processing routes such as ECAP, ARB, HPT and FSP have been considered and their effect on mechanical properties, especially at intermediate to high temperatures, are studied. Refined grains as fine as 100 nm and average misorientations as high as 39o allow attainment of high strain rate superplasticity (HSRSP) at lower than usual temperatures (250-300oC). It is shown that increasing misorientations are obtained with increasing applied strain, and increasing grain refinement is obtained with increasing processing stress. Thus, increasing superplastic strains at higher strain rates, lower stresses and lower temperatures are obtained with increasing processing strain and, specially, processing stress.


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