Improvement of Microstructure and Mechanical Properties of 7050-T7451 Aluminum by a Novel Double-Sided Friction Stir Processing

Abstract:

Recently, friction stir processing (FSP), as an effective tool, has been employed to modify microstructures and mechanical properties of metal sheet. A novel technique of double surface friction stir processing (FSP) was proposed in this study. A 7050-T7451 aluminum alloy sheet of 6.5mm in thickness was processed by FSP with 30% overlap in each side. The position deviation of the stir pin from the upper surface to the bottom surface is 35%. Significant grain refinement with an average grain size of 2.5μm from the as-received 50μm, can be obtained after double-sided FSP. In comparison with the conventional FSP, no HAZ (heat affected zone) or TMAZ (thermal mechanical affected zone) was formed between the adjacent stir zones of the aluminum alloy sheet. At a strain rate of 10^-3 s^-1, a maximum elongation of 29.8% and 327% in transverse direction of FSP passes have been achieved at room temperature and 400°C, respectively.

• Periodical: Materials Science Forum (Volumes 838-839)
• Pages: 385-391
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.838-839.385
• Online since: January 2016
• Authors: Wen Jing Yang, Ji Zhong Li, Xue Wen, Hua Ding*
• Keywords: Aluminium Alloy, Double Surface, Friction Stir Processing, Superplasticity

References

[1] Musin F, Kaibyshev R, Motohashi Y, et al., High strain rate superplasticity in a commercial Al–Mg–Sc alloy, Scripta Materialia, 2004, 50(4): 511-516.

DOI: 10.1016/j.scriptamat.2003.10.021

[2] Park K T, Lee H J, Lee C S, et al., Effect of ECAP strain on deformation behavior at low temperature superplastic regime of ultrafine grained 5083 Al alloy fabricated by ECAP, Materials Transactions, 2004, 45(3): 958-963.

DOI: 10.2320/matertrans.45.958

[3] Kaibyshev R, Sakai T, Nikulin I, et al., Superplasticity in a 7055 aluminum alloy subjected to intense plastic deformation, Materials science and technology, 2003, 19(11): 1491-1497.

DOI: 10.1179/026708303225008167

[4] Tsuji N, Ito Y, Saito Y, et al., Strength and ductility of ultrafine grained aluminum and iron produced by ARB and annealing, Scripta Materialia, 2002, 47(12): 893-899.

DOI: 10.1016/s1359-6462(02)00282-8

[5] Noda M, Hirohashi M, Funami K, Low temperature superplasticity and its deformation mechanism in grain refinement of Al-Mg alloy by multi-axial alternative forging, Materials Transactions, 2003, 44(11): 2288-2297.

DOI: 10.2320/matertrans.44.2288

[6] Mishra R S, Mahoney M W, McFadden S X, et al., High strain rate superplasticity in a friction stir processed 7075 Al alloy, Scripta Materialia, 1999, 42(2): 163-168.

DOI: 10.1016/s1359-6462(99)00329-2

[7] Charit I, Mishra R S, High strain rate superplasticity in a commercial 2024 Al alloy via friction stir processing, Materials Science and Engineering: A, 2003, 359(1): 290-296.

DOI: 10.1016/s0921-5093(03)00367-8

[8] Liu F C, Xiao B L, Wang K, et al., Investigation of superplasticity in friction stir processed 2219Al alloy, Materials Science and Engineering: A, 2010, 527(16): 4191-4196.

DOI: 10.1016/j.msea.2010.03.065

[9] Yadav D, Bauri R, Effect of friction stir processing on microstructure and mechanical properties of aluminium, Materials Science and Engineering: A, 2012, 539: 85-92.

DOI: 10.1016/j.msea.2012.01.055

[10] Jana S, Mishra R S, Baumann J A, et al., Effect of process parameters on abnormal grain growth during friction stir processing of a cast Al alloy, Materials Science and Engineering: A, 2010, 528(1): 189-199.

DOI: 10.1016/j.msea.2010.08.049

[11] Mahmoud T S, Mohamed S S, Improvement of microstructural, mechanical and tribological characteristics of A413 cast Al alloys using friction stir processing, Materials Science and Engineering: A, 2012, 558: 502-509.

DOI: 10.1016/j.msea.2012.08.036

[12] Charit I, Mishra R S, High strain rate superplasticity in a commercial 2024 Al alloy via friction stir processing, Materials Science and Engineering: A, 2003, 359(1): 290-296.

DOI: 10.1016/s0921-5093(03)00367-8

[13] Ma Z Y, Mishra R S, Mahoney M W, et al., High strain rate superplasticity in friction stir processed Al–Mg–Zr alloy, Materials Science and Engineering: A, 2003, 351(1): 148-153.

DOI: 10.1016/s0921-5093(02)00824-9

[14] Charit I, Mishra R S, Low temperature superplasticity in a friction-stir-processed ultrafine grained Al–Zn–Mg–Sc alloy, Acta Materialia, 2005, 53(15): 4211-4223.

DOI: 10.1016/j.actamat.2005.05.021

[15] Berbon P B, Bingel W H, Mishra R S, et al., Friction stir processing: a tool to homogenize nanocomposite aluminum alloys, Scripta Materialia, 2001, 44(1): 61-66.

DOI: 10.1016/s1359-6462(00)00578-9

[16] Zhang Z, Liu Y L, Chen J T, Effect of shoulder size on the temperature rise and the material deformation in friction stir welding, The International Journal of Advanced Manufacturing Technology, 2009, 45(9-10): 889-895.

DOI: 10.1007/s00170-009-2034-7

[17] Tang W, Guo X, McClure JC, Murr LE, J Mater Process Manuf Sci 1998; 7: 163.

[18] El Rayes M M, El Danaf E A, Soliman M S, High-temperature deformation and enhanced ductility of friction stir processed-7010 Aluminum Alloy, Materials & Design, 2011, 32(4): 1916-(1922).

DOI: 10.1016/j.matdes.2010.12.004

[19] Al-Fadhalah K J, Almazrouee A I, Aloraier A S, Microstructure and mechanical properties of multi-pass friction stir processed aluminum alloy 6063, Materials & Design, 2014, 53: 550-560.

DOI: 10.1016/j.matdes.2013.07.062