Superplasticity in a 5024 Aluminium Alloy Subjected to ECAP and Subsequent Cold Rolling

2016 ◽  
Vol 838-839 ◽  
pp. 428-433 ◽  
Author(s):  
Anna Mogucheva ◽  
Diana Yuzbekova ◽  
Rustam Kaibyshev

The superplastic behavior of an 5024 alloy, subjected to equal-channel angular pressing (ECAP) followed by extensive cold rolling (CR), was studied in the temperature range 250-500°C and at strain rates ranging from 10–4 to 10–1 s–1. The maximum elongation-to failure of ~1440% with a corresponding strain rate sensitive coefficient m of ~0.42 was attained at 450°C and a strain rate of ~1.4×10–1 s–1. The relationship between superplastic properties and microstructure of the alloy was discussed.

2016 ◽  
Vol 838-839 ◽  
pp. 422-427 ◽  
Author(s):  
Diana Yuzbekova ◽  
Anna Mogucheva ◽  
Rustam Kaibyshev

The ultrafine grained structure of an AA5024 with an average size of ∼0.7 μm was produced by equal-channel angular pressing (ECAP) at 300°C with a total strain of ~12. Superplastic behavior of this alloy was examined in the temperature interval 175 - 300°C at strain rates ranging from 10-4 to 10-1 s-1. The maximum elongation-to-failure of ~1200% with the corresponding strain rate sensitivity coefficient, m, of ∼0.49 was attained at a temperature of 275°C and a strain rate of 5.6×10–3s–1. At 175°C (~0.53Tm, where Tm is the melting point), the elongation-to-failure of ~370% with the m value of ~0.3 was found at ε̇=1.4×10–4 s–1.


2012 ◽  
Vol 706-709 ◽  
pp. 395-401 ◽  
Author(s):  
A. Smolej ◽  
B. Skaza ◽  
B. Markoli ◽  
Damjan Klobčar ◽  
V. Dragojević ◽  
...  

The aim of the present investigation was to determine and to compare the superplastic behaviour of the AA5083 (Al-Mg-Mn) alloy with Sc and Zr additions. The investigated alloys were processed to form sheets by conventional hot and cold rolling. The superplastic properties were determined with strain rates in the range of 1x10-4to 5x10-2s-1and forming temperatures of 350 to 550°C. The results showed that the alloy with about 0.4% Sc exhibited a high superplastic ductility across a wide temperature range and strain rates up to 1x10-2s-1. The highest elongations to failure of about 2000% were attained at 550°C and at an initial strain rate of 5x10-3s-1. However, the alloy with about 0.15% Zr exhibited elongations up to 600%. The FSP processed Al-4.5Mg alloy with combined addition of about 0.2% Sc and 0.15% Zr exhibited good superplastic properties at higher strain rates (> 1x10-2s-1) with elongations up to 1500%.


2012 ◽  
Vol 735 ◽  
pp. 353-358 ◽  
Author(s):  
Anna Mogucheva ◽  
Diana Tagirova ◽  
Rustam Kaibyshev

The superplastic behaviour of an Al-4.6%Mg-0.35%Mn-0.2%Sc-0.09%Zr alloy was studied in the temperature range 250-500°C at strain rates ranging from 10-4 to 10-1 s-1. The AA5024 was subjected to equal channel angular pressing (ECAP) at 300°C up to ~12. The highest elongation-to-failure of ∼3300% was attained at a temperature of 450°C and an initial strain rate of 5.6×10-1 s-1. Regularities of superplastic behaviour of the 5024 aluminium alloy are discussed.


2016 ◽  
Vol 838-839 ◽  
pp. 416-421 ◽  
Author(s):  
Andrii Dubyna ◽  
Sergey Malopheyev ◽  
Rustam Kaibyshev

The superplastic behavior of a commercial aluminum alloy denoted as 1570 Al with a chemical composition of Al-6%Mg-0.5%Mn-0.2%Sc-0.07%Zr (in wt. %) and ultrafine-grained (UFG) structure produced by equal channel angular pressing at 300°C to a true strain ~12 was studied after final cold or warm rolling. The tensile specimens were machined along rolling direction and pulled up to failure in the temperature range of 250 to 500°C at strain rates ranging from 10-4 s-1 to 10-1 s-1. The specimens produced by warm or cold rolling exhibit different superplastic behavior. The material subjected to warm rolling exhibits excellent superplastic properties; the highest elongation-to-failure of ~1970% was recorded at a temperature of ~450°C and an initial strain rate of 1.4×10-1 s-1. On the other hand, the material subjected to cold rolling demonstrates moderate superplastic properties; the highest elongation-to-failure of ~755% appears at a temperature of ~300°C and an initial strain rate of 1.4×10-2 s-1.


2021 ◽  
Vol 1016 ◽  
pp. 928-933
Author(s):  
Anna Mogucheva ◽  
Diana Yuzbekova ◽  
Yuliya Igorevna Borisova

An Al-3Mg (wt. %) alloy was studied after equal channel angular pressing and subsequent cold rolling. The mechanical behavior of the alloy in the temperature range from 223 K to 373 K (from –50°C to 125°C) at strain rates 2.1×10–1 – 5.2×10–5 s–1 was investigated. The analysis of stress-strain curves was performed to determine the conditions of manifestation of the Portevin – Le Chatelier (PLC) effect in investigated alloy. The deformation curve at a temperature of 298 K (25°C) and a strain rate of 1×10–3 s–1 is characterized by instability of plastic flow in contrast to the deformation curves obtained under other studied strain rate/temperature conditions. Stress oscillations at the necking stage were observed at high temperatures (>323 K (50°C)) and lower strain rates (1×10–4 s–1 and 5.2×10–5 s–1) forming the left border of the PLC effect domain. In general, deformation curves are characterized by the absence of stress serrations during the uniform elongation.


2012 ◽  
Vol 735 ◽  
pp. 347-352
Author(s):  
Ilya Nikulin ◽  
Alla Kipelova ◽  
Rustam Kaibyshev

An ultra-fine grained structure with an average size of ~ 1 μm was produced in a commercial Al–5.4%Mg–0.5%Mn–0.1%Zr–0.12%Si–0.014%Fe alloy by hot equal-channel angular pressing (ECAP) followed by isothermal rolling (IR). It was found that in the strain rate interval from 5.6×10-4to 2.8×10-2s-1the alloy exhibits a low-temperature superplasticity with elongation-to-failure exceeding 400% and the strain rate sensitivity coefficient of ~0.3. The highest elongation-to-failure of ~ 620% appeared at a temperature of ~ 275°C and an initial strain rate of ~ 5.6×10-3s-1. The relationship between superplastic properties and microstructural evolution of the examined alloy is discussed.


2016 ◽  
Vol 838-839 ◽  
pp. 338-343 ◽  
Author(s):  
Sergey Malopheyev ◽  
Sergey Mironov ◽  
Igor Vysotskiy ◽  
Rustam Kaibyshev

The commercial Al-5.4Mg-0.2Sc-0.1Zr alloy was subjected to equal-channel angular pressing at 300°C to a true strain ~12 followed by cold rolling to a total thickness reduction of 80%. The ultrafine-grained sheets were joined by friction stir welding (FSW). To evaluate superplastic properties of the weldments, the tensile samples including all of the characteristic FSW microstructural zones were machined perpendicular to the welding direction and pulled up to failure in the temperature range of 400 to 500°C and at strain rates of 2.8×10-4 s-1 to 5.6×10-1 s-1. The friction-stir welded material exhibited excellent superplastic properties. The highest elongation-to-failure of ~1370% was recorded at a temperature of ~450°C and an initial strain rate of 5.6×10-2 s-1, where the strain rate sensitivity coefficient was about 0.64. The relationship between superplastic ductility and microstructure is discussed.


2015 ◽  
Vol 830-831 ◽  
pp. 345-349 ◽  
Author(s):  
Elena Avtokratova ◽  
Oleg Sitdikov ◽  
Oksana Mukhametdinova ◽  
Michael Markushev ◽  
S.V.S. Narayana Murty ◽  
...  

The feasibility has been demonstrated for achieving high-strain-rate superplasticity with elongations beyond 2000% in Al-Mg-Sc-Zr alloy with the partially recrystallized structure, produced by warm equal-channel angular pressing to strain of e~3 only. Subsequent alloy ambient temperature rolling up to e~1.6 enhanced the superplastic elongations and moved the optimum of superplasticity toward the higher strain rates.


2016 ◽  
Vol 870 ◽  
pp. 185-190
Author(s):  
F.F. Musin ◽  
B.O. Bolshakov ◽  
E. Domracheva

The superplastic properties and microstructural evolution of a commercial Al-4.4%Cu-0.5%Mg-0.4%Mn-0.5%Ag-0.1%Ti alloy were examined under tension at temperatures ranging from 450 to 520°C and strain rates ranging from 6.9x10-5 to 6.9x10-2s-1. The refined microstructure with an average grain size of about 11m was produced in thin sheets by a commercially viable thermomechanical process. The highest elongation to failure of 540% was attained at a temperature of 500°C and an initial strain rate of 6.9x10-4 s-1 with the corresponding strain rate sensitivity coefficient of 0.55. The microstructural evolution during superplastic deformation of the aluminum alloy has been studied quantitatively. Processing at temperatures above 475°C and strain rate below 1.4x10-3s-1 resulted in fracturing almost without necking with cavitation playing a major role in the failure. In contrast, at low temperatures and/or high strain rates, fracture occurred in a ductile manner by localized necking. The relationship between superplastic ductility and microstructural evolution is analyzed.


2010 ◽  
Vol 667-669 ◽  
pp. 815-820 ◽  
Author(s):  
Sergey Malopheyev ◽  
Alla Kipelova ◽  
Ilya Nikulin ◽  
Rustam Kaibyshev

Superplasticity and microstructural evolution of a commercial Al-5.4%Mg-0.5%Mn-0.1%Zr alloy subjected to severe plastic deformation through equal-channel angular pressing (ECAP) and subsequent rolling was studied in tension at strain rates ranging from 1.4×10-4 to 5.6×10-2 s-1 in the temperature interval 400-550°C. The alloy had an unrecrystallized microstructure with an average crystallite size less than 5 m. The alloy exhibited the yield strength of ~370 MPa, ultimate strength of ~450 MPa and elongation-to-failure of ~15% at ambient temperature. In spite of small crystallite size the alloy shows moderate superplastic properties. The highest elongation-to-failures of ~450% appeared at a temperature of ~500°C and an initial strain rate of ~1.4×10-3 s-1, where the strain rate sensitivity coefficient, m, is of about 0.57. The relationship between superplastic ductilities and microstructure is discussed.


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