Superplastic Behavior of Copper-Modified 5083 Aluminum Alloy

Abstract

An AA5083 aluminum alloy was modified with two different levels of Cu additions, cast by direct-chill method, and thermo-mechanically processed to sheet gauge. Copper additions reduced sheet grain size, decreased tensile flow stress and significantly increased tensile elongation under most elevated temperature test conditions. The high-Cu (0.8 wt.%) alloy had the finest grain size 5.3 lm, a peak strain-rate sensitivity of 0.6 at a strain-rate of 1 · 10 )2 s )1 , and tensile elongation values between 259 and 584% over the temperature range, 400-525°C, and the strain rate range, 5 · 10 )4 to 1 · 10 )2 s )1 , investigated. In biaxial pan forming tests, only the Cu-containing alloys successfully formed pans at the higher strain rate 10 )2 s )1 . The high-Cu alloy showed the least die-entry thinning. Comparison of ambient temperature mechanical properties in O-temper state showed the high-Cu alloy to have significantly higher yield strength, ultimate strength, and ductility compared to the base 5083 alloy.

Superplastic Behavior of Al-4.5Mg-0.46Mn-0.44Sc Alloy Sheet Produced by a Conventional Rolling Process

“…There are a lot of earlier reports on superplasticity for standard Al-Mg-Mn (5083) alloys that were thermomechanically processed ( Ref 2,3,5,6,8,9,12,13). This alloy, without any Sc addition, exhibited elongations to failure, mostly up to 600%, with m-values in the range of 0.4 to 0.65 at strain rates from 1 9 10 À4 to 1 9 10 À2 s À1 and at temperatures of 450 to 550°C.…”

“…The superplastic behavior of this alloy has been investigated extensively (Ref [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. These investigations have included the superplastic-related characteristics, such as the manufacturing processes of the alloy, the microstructure, the flow stresses, the maximum tensile elongations to failure, the strain-rate sensitivity indexes, the optimum working conditions for achieving these properties, the mechanisms of superplastic behavior, and models of superplastic deformation using the finite-element method ( Ref 11,14,16).…”

“…Good superplastic formability under the above-mentioned working conditions can be achieved by making a further reduction in the grain size of the material ( Ref 19). There are several methods for modifying the grain sizes: (1) an appropriate thermomechanical treatment involving high reductions of material during cold rolling, (2) new forming processes, such as equal channel angular pressing (ECAP) and high-pressure torsion and accumulative roll-bonding ( Ref 19,20,[22][23][24], and (3) minor additions of Cu, Cr, Zr, and Sc to the base alloy ( Ref 7,12,[25][26][27].…”

Microstructure and Mechanical Properties of Al-5Mg-0.8Mn Alloys with Various Contents of Fe and Si Cast under Near-Rapid Cooling

“…Extensive research to improve the AA5083 alloy had been conducted with emphasis on the microstructures and mechanical properties [8][9][10][11], superplasticity [12][13][14][15], ultrafine grain [16][17][18][19][20] and adding element [21][22][23][24], etc. Recently, research was carried out on the formation of the Fe-and Mn-rich intermetallics in the AA5083 type Al-Mg-Mn alloy [2].…”

Finite element analysis of superplastic blow-forming of Ti-6Al-4V sheet into closed ellip-cylindrical die

“…The validity of the pressure prediction algorithm used in the numerical solution procedure was confirmed by comparing the numerical results with the experimental observations. Verma and Kim [13] investigated and understand the effect of Cu additions on both elevated temperature formability and ambient temperature mechanical properties of AA5083 alloy. A detailed FE analysis of superplastic gas-blow forming was carried out using a modified microstructure-based constitutive model that accounts for grain growth and cavitation by Nazzal et al [14].…”