Evaluation of Post-Weld Heat Treatments to Restore the Corrosion Resistance of Friction Stir Welded Aluminum Alloy 7075-T73 vs. 7075-T6


Article Preview

Friction stir welding (FSW) is rapidly becoming accepted as a viable manufacturing process for aerospace applications. One potential area of concern, however, is the corrosion resistance of some FSW joints. While the corrosion resistance of friction stir welded 7075 aluminum has been investigated, and attempts made to enhance its corrosion resistance through different combinations of starting temper and post-weld artificial aging (PWAA) treatments, a clear approach for selecting pre-temper conditions and PWAA processing has not emerged. For this investigation, FSW butt-welds in sheets of 0.125-inch 7075-T73 and 7075-T6 were given a variety of PWAA treatments, some of which were developed previously by other authors. Thermal treatments were evaluated using optical microscopy, exfoliation, electrical conductivity, microhardness, tensile, and fatigue crack propagation testing. An important conclusion drawn from this work is that 7075-T73 can be friction stir welded and post-weld aged in a manner that produces superior exfoliation resistance and good mechanical properties without invalidating the bulk parent material temper specified in AMS 2770G.



Materials Science Forum (Volumes 539-543)

Main Theme:

Edited by:

T. Chandra, K. Tsuzaki, M. Militzer , C. Ravindran




C. A. Widener et al., "Evaluation of Post-Weld Heat Treatments to Restore the Corrosion Resistance of Friction Stir Welded Aluminum Alloy 7075-T73 vs. 7075-T6", Materials Science Forum, Vols. 539-543, pp. 3781-3788, 2007

Online since:

March 2007




[1] Thomas, W.M., et al., Friction Stir Welding, U.S. Patent No. 5, 460, 317, October, 24, (1995).

[2] Klæstrup Kristensen, J. et al. Properties of Friction Stir Welded Joints in Aluminum Alloys 2024, 5083, 6082/6060 and 7075, 5th Intl. Friction Stir Welding Symposium, September, (2004).

DOI: 10.1002/9781118062302.ch26

[3] Heat Treatment of Wrought Aluminum Alloy Parts, Aerospace Material Specification, AMS 2770G, April, (2003).

[4] Nelson, T.W., Steel, R.J., and Arbegast, W.J., Investigation of Heat Treatment on the Properties of Friction Stir Welds, ASM International Aeromat Conference Presentation, (2001).

[5] Leonard, A.J., Corrosion Resistance of Friction Stir Welds in Aluminum Alloys 2014A-T651 and 7075-T651, 2nd International Friction Stir Welding Symposium, 26-28 June, (2000).

DOI: 10.4028/www.scientific.net/ssp.231.93

[6] Anonymous. Corrective Measures to Restore Corrosion Resistance Following Friction Stir Welding, Office of Naval Research, Report no. A580234, Rockwell Scientific, (2004).

DOI: 10.21236/ada432085

[7] Kumar, B. et al. Applicability of FSW for Aircraft Applications, 46th AIAA SDM Conf., (2005).

[8] Paglia, C.S. et al. Corrosion and Environmentally Assisted Cracking Behavior of High Strength Al Alloys FSW: 7075-T651vs. 7050-T7451, FSW and Processing II, 2003, pp.65-75.

[9] Lumsden, J., Mahoney, M., and Pollock, G., Stress Corrosion Susceptibility in 7050-T7451 Aluminum Following FSW, 1st International Friction Stir Welding Symposium, June, (1999).

[10] Merati, A., Sarda, K., Raizenne, D., Dalle Done, C., Improving Corrosion Properties of Friction Stir Welded Al Alloys by Localized Heat Treatment, FSW and Processing II, 2003, pp.77-90.

[11] Li, Z.X., Arbegast, W.J., Wilson, A.L., Moran, J., and Liu, J., Post-Weld Aging of Friction Stir Welded 7249 Extrusions, Trends in Welding Research Conference, 15-19 April, 2002, pp.312-317.

[12] Pao, P.S., Gill, S.J., Feng, C.R., and Sankaran, K.K., Effects of Weld Microstructure on Fatigue Crack Growth in Friction Stir Welded Al 7050, TMS Aluminum 2001, 2001, pp.265-279.

DOI: 10.1016/s1359-6462(01)01070-3

[13] Sankaran, K.K., Smith, H.L., and Jata, K., Pitting Corrosion Behavior of Friction Stir Welded 7050-T74 Aluminum Alloy, Trends in Welding Research, April, 2002, pp.284-286.

[14] Paglia, C.S. et al. Investigating Post-weld Heat Treatments to Increase the Corrosion and Environmental Cracking Behavior of 7075-T6 FSW, Trends in Welding Research, 2002, pp.279-283.

[15] Lumsden, J., Pollock, G., and Mahoney, M., Effect of Post Weld Heat Treatments on the Corrosion Properties of FSW AA7050, FSW and Processing II, TMS, March, 2003, pp.99-106.

[16] Dunlavy, M., and Jata, K.V., High-Cycle Corrosion Fatigue of Friction Stir Welded 7050-T7451, Friction Stir Welding and Processing II, 2-6 March, 2003, pp.91-98.

[17] Dawes, M.G., Karger, S.A., Dickerson, T.L., and Pryzdatek, J., Strength and Fracture Toughness of FSW in Al Alloys, 2nd Intl. Friction Stir Welding Symposium, 26-28 June, (2000).

[18] James, M., Mahoney, M., and Waldron, D., Residual Stress Measurements in Friction Stir Welded Aluminum Alloys, 1st International Friction Stir Welding Symposium, 14-16 June, (1999).

DOI: 10.1002/9781118062302.ch32

[19] Dalle Donne, C., Biallas, G., Ghindini, T., Raimbeaux, G., Effect of Weld Imperfections and Residual Stresses on FCP in FSW Joints, 2nd International Symposium on FSW, 8 June, (2000).

[20] John, R., and Jata, K.V., Residual Stress Effects on Near-Threshold Fatigue Crack Growth in Friction Stir Welds, Friction Stir Welding and Processing, 4-8 November, 2001, pp.57-69.

DOI: 10.1016/j.ijfatigue.2003.08.002

[21] Bussu, G., and Irving, P.E., The Role of Residual Stress and HAZ Properties on FCP in Friction Stir Welded 2024-T351 Al Joints, Intl. Jrnl. Fatigue, v. 25, n. 1, Jan., 2003, pp.93-104.

DOI: 10.1016/s0142-1123(02)00038-5

[22] Ferrer, C.P. et al. Improvements in Strength and SCC Properties in Al Alloy 7075 via Low-Temperature RRA Heat Treatments, Corrosion, vol. 59, no. 6, June, 2003, pp.520-528.

Fetching data from Crossref.
This may take some time to load.