Effect of Zr on Structure and Resistance to Intergranular Corrosion of Severely Deformed 2024 Aluminum Alloy

Author(s):  
Stanislav Krymskiy ◽  
Rafis Ilyasov ◽  
Elena Avtokratova ◽  
Oleg Sitdikov ◽  
Anastasia Khazgalieva ◽  
...  

Effects of severe plastic deformation by isothermal сryorolling with a strain of e~2 and subsequent natural and artificial aging on the structure and resistance to intergranular corrosion (IGC) of the preliminary quenched 2024 aluminum alloy of standard and Zr modified compositions were investigated. Increasing the temperature of aging leads to decreasing the alloy IGC resistance due to precipitation of more stable strengthening S-phase (Al2CuMg), rising difference of electrochemical potentials at grain and subgrain boundaries. Zr additions, оn the opposite, significantly increased the alloy IGC resistance in both naturally and artificially aged conditions, reducing its depth and intensity. The main structural factor, influencing the alloy corrosion behavior, is excess phases: their composition, volume fraction and distribution.

2014 ◽  
Vol 880 ◽  
pp. 179-183
Author(s):  
Evgeniy V. Naydenkin ◽  
Konstantin V. Ivanov ◽  
Gennadiy E. Rudenskii

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.


2010 ◽  
Vol 667-669 ◽  
pp. 925-930
Author(s):  
S.V. Krymskiy ◽  
Elena Avtokratova ◽  
M.V. Markushev ◽  
Maxim Yu. Murashkin ◽  
O.S. Sitdikov

The effects of severe plastic deformation (SPD) by isothermal rolling at the temperature of liquid nitrogen combined with prior- and post-SPD heat treatment, on microstructure and hardness of Al-4.4%Cu-1.4%Mg-0.7%Mn (D16) alloy were investigated. It was found no nanostructuring even after straining to 75%. Сryodeformation leads to microshear banding and processing the high-density dislocation substructures with a cell size of ~ 100-200 nm. Such a structure remains almost stable under 1 hr annealing up to 200oC and with further temperature increase initially transforms to bimodal with a small fraction of nanograins and then to uniform coarse grained one. It is found the change in the alloy post–SPD aging response leading to more active decomposition of the preliminary supersaturated aluminum solid solution, and to the alloy extra hardening under aging with shorter times and at lower temperatures compared to T6 temper.


JOM ◽  
2018 ◽  
Vol 70 (11) ◽  
pp. 2731-2738 ◽  
Author(s):  
I. Zhukov ◽  
V. Promakhov ◽  
S. Vorozhtsov ◽  
A. Kozulin ◽  
A. Khrustalyov ◽  
...  

2012 ◽  
Vol 186 ◽  
pp. 331-334
Author(s):  
Mateusz Kopyściański ◽  
Stanislaw Dymek ◽  
Carter Hamilton

This research characterizes the changes in microstructure that occur in friction stir welded extrusions of a novel 7042 aluminum alloy. Due to the presence of scandium the base material preserved the deformation microstructure with elongated grains and fairly high dislocation density. The temperature increase with simultaneous severe plastic deformation occurring during friction stir welding induced significant changes in the microstructure within the weld and its vicinity. The weld center (stir zone) was composed of fine equiaxed grains with residual dislocations and a modest density of small precipitates compared to the neighbouring thermomechanically and heat affected zones where the density of small precipitates was much higher.


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