Microstructural characterization and corrosion behavior of multipass friction stir processed AA2219 aluminium alloy

Surekha, K.; Murty, B.S.; Rao, K. Prasad

doi:10.1016/j.surfcoat.2008.02.001

Cited by 122 publications

(46 citation statements)

References 25 publications

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“…Two major precipitates (Al 2 Cu (θ) and Al 2 CuMg (S) phases) are present in the 2xxx series of Cu-containing aluminum alloys, leading to pitting and intergranular corrosion. The θ phase acts as the cathode and accelerates the dissolution of the adjacent matrix [12][13]24]. The S phase acts as the anode and can resist corrosion attack in early stages, but will lead to the dissolution of the adjacent matrix with increasing immersion time [11,29−30].…”

Section: Introductionmentioning

confidence: 99%

Corrosion behavior of the friction-stir-welded joints of 2A14-T6 aluminum alloy

Qin

Zhang

Sun³

et al. 2015

Int J Miner Metall Mater

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Abstract:The corrosion behavior of friction-stir-welded 2A14-T6 aluminum alloy was investigated by immersion testing in immersion exfoliation corrosion (EXCO) solution. Electrochemical measurements (open circuit potential, potentiodynamic polarization curves, and electrochemical impedance spectroscopy), scanning electron microscopy, and energy dispersive spectroscopy were employed for analyzing the corrosion mechanism. The results show that, compared to the base material, the corrosion resistance of the friction-stir welds is greatly improved, and the weld nugget has the highest corrosion resistance. The pitting susceptibility originates from the edge of Al−Cu−Fe−Mn−Si phase particles as the cathode compared to the matrix due to their high self-corrosion potential. No corrosion activity is observed around the θ phase (Al 2 Cu) after 2 h of immersion in EXCO solution.

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Section: Introductionmentioning

confidence: 99%

Corrosion behavior of the friction-stir-welded joints of 2A14-T6 aluminum alloy

Qin

Zhang

Sun³

et al. 2015

Int J Miner Metall Mater

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“…In FSP NAB, the morphology of the K phases has changed, and segregation is improved, and hence increasing the corrosion resistance. Surekha et al [29] state that the FSP increases the immersion, electrochemical, and salt spray corrosion resistance of AA 2219-T87 alloy in NaCl solution. The corrosion resistance increases as the number of FSP cycles is increased and also as the FSP tool rotational speed is increased.…”

Section: Corrosion Testingmentioning

confidence: 99%

Feasibility Study of Low Force Robotic Friction Stir Process and its Effect On Cavitation Erosion and Electrochemical Corrosion for Ni Al Bronze Alloys

Ahmad

Pan

et al. 2014

Metall Mater Trans B

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Robotic friction stir processing (FSP) has not been widely researched to date. This is perhaps due to the limited force capabilities of industrial robots in comparison with dedicated commercial FSP equipment. When operating a FSP machine, the force used to plunge the tools may range from 5000 to 8000 N which is currently beyond the capability of most robots. However, the capacity of robotic manipulators is increasing, so low force friction stir processing is becoming feasible. The ability of the robot arm to apply a controlled force that is normal to a 3-dimensional surface without the need to reorient the workpiece makes it a very useful tool for FSP of complex components. In this analysis, a robot arm with a capacity of 2500 N is used to improve the surface properties of nickel aluminum bronze (NAB) using low force FSP. Multiple passes were applied to the surface of the test sample for a more consistent spread of the stir zone. The sample was then microhardness tested and demonstrated a 62 pct increase in surface hardness. Cavitation erosion testing of the original and processed surfaces was also performed as per ASTM G-32. The erosion rate of the processed NAB sample was 44 pct of the rate experienced by the original cast NAB sample. Finally, the corrosion potentials of FSP NAB were measured at 45 mV less anodic than the unprocessed material, indicating that the processed material is more noble relative to the cast NAB sample. Robotic friction stir processing (FSP) has not been widely researched to date. This is perhaps due to the limited force capabilities of industrial robots in comparison with dedicated commercial FSP equipment. When operating a FSP machine, the force used to plunge the tools may range from 5000 to 8000 N which is currently beyond the capability of most robots. However, the capacity of robotic manipulators is increasing, so low force friction stir processing is becoming feasible. The ability of the robot arm to apply a controlled force that is normal to a 3-dimensional surface without the need to reorient the workpiece makes it a very useful tool for FSP of complex components. In this analysis, a robot arm with a capacity of 2500 N is used to improve the surface properties of nickel aluminum bronze (NAB) using low force FSP. Multiple passes were applied to the surface of the test sample for a more consistent spread of the stir zone.The sample was then microhardness tested and demonstrated a 62 pct increase in surface hardness. Cavitation erosion testing of the original and processed surfaces was also performed as per ASTM G-32. The erosion rate of the processed NAB sample was 44 pct of the rate experienced by the original cast NAB sample. Finally, the corrosion potentials of FSP NAB were measured at 45 mV less anodic than the unprocessed material, indicating that the processed material is more noble relative to the cast NAB sample.

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“…At the same time, the second phases containing active elements and inactive elements forma corrosion galvanic couple. The second phases containing the inactive elements become the cathode, and the second phases containing the active element, as an anode, form anodic dissolution [26,[28][29][30][31].…”

Section: Introductionmentioning

confidence: 99%

Corrosion Behavior of Keyhole-Free Friction Stir Spot Welded Joints of Dissimilar 6082 Aluminum Alloy and DP600 Galvanized Steel in 3.5% NaCl Solution

Zhang

et al. 2017

Metals

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Abstract:The corrosion behavior of keyhole-free friction stir spot welded joints of dissimilar 6082 aluminum alloy and DP600 galvanized steel in 3.5% NaCl solution has been investigated by the immersion test and electrochemical analysis. The surface of the aluminum alloy produced exfoliation and pitting corrosion. The pitting occurred seriously on the interface of the 6082 aluminum alloy, but the steel had no corrosion. The corrosion galvanic couples were formed between elements of Si and Fe with a high electrode potential, and Mg and Al with a low electrode potential, around them. Mg and Al elements of Mg 2 Si and Si-containing solid-solution phase α (Al) preferentially became an anodic dissolution and formed exfoliation corrosion around the Si elements. Fe-rich phase θ (Al 3 Fe) as the cathode caused corrosion of Mg and formed pitting around Mg-rich phase β (Al 3 Mg 2 ) as the anode. The sequence of the corrosion resistance of different areas of the joints (with decreasing corrosion resistance) was WNZ (Weld Nugget Zone) > TMAZ (Thermo-mechanically Affected Zone) > BM (Base Metal) > HAZ (Heat-affected Zone). The joints of keyhole-free FSSW (Fiction Stir Spot Welding) of dissimilar 6082 aluminum alloy and DP600 galvanized steel have better corrosion resistance than base metal in 3.5% NaCl solution.

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Microstructural characterization and corrosion behavior of multipass friction stir processed AA2219 aluminium alloy

Cited by 122 publications

References 25 publications

Corrosion behavior of the friction-stir-welded joints of 2A14-T6 aluminum alloy

Corrosion behavior of the friction-stir-welded joints of 2A14-T6 aluminum alloy

Feasibility Study of Low Force Robotic Friction Stir Process and its Effect On Cavitation Erosion and Electrochemical Corrosion for Ni Al Bronze Alloys

Corrosion Behavior of Keyhole-Free Friction Stir Spot Welded Joints of Dissimilar 6082 Aluminum Alloy and DP600 Galvanized Steel in 3.5% NaCl Solution

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