Mechanical Performance of Heat Treated Ti-6Al-4V Friction Stir Welds

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Abstract:

Heat treatment processes for standard fusion welding techniques in titanium are well established, but the optimal heat treatment for Friction Stir Welded titanium has not been evaluated. In this study, 6 mm thickness titanium 6Al-4V butt welds were subjected to heat treatments ranging from 700 to 900 C. Results of the metallographic analysis for each heat treatment condition will be presented in addition to microhardness, tensile and fatigue properties. It was found that increased heat treatment temperatures lead to lower hardness and tensile strengths, higher elongation to failure and improved high cycle fatigue performance. Furthermore, fracture toughness and crack growth tests were performed for welds subjected to a standard post-weld stress relief. The fracture toughness was lower than the parent material, but crack growth rates in the weld were similar to that of the base metal.

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213-221

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May 2010

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[1] P. Edwards, M. Ramulu, 2009, Investigation of microstructure, surface and subsurface characteristics in titanium alloy friction stir welds of varied thicknesses, Science and Technology of Welding and Joining, Vol. 14, No 5, pp.775-782.R. S.

DOI: 10.1179/136217109x425838

Google Scholar

[2] T.J. Lienert, 2007, Microstructure and Mechanical Properties of Friction Stir Welded Titanium Alloys, Friction Stir Welding and Processing, ASM International, Materials Park, OH, Ch. 7, pp.123-154.

DOI: 10.1002/9781118062302.ch16

Google Scholar

[3] D. Sanders, M. Ramulu, E. Klock-McCook, P. Edwards, A. Reynolds, T. Trapp, Characterization of Superplastically Formed Friction Stir Weld in Titanium 6Al-4V: Preliminary Results, " Journal of Mat, ls. Engr. & Perf., Vol. 17, No. 2, pp.187-192, (2008).

DOI: 10.1007/s11665-007-9186-0

Google Scholar

[4] Y. Zhang, Y. S. Sato, H. Kokawa, S. H. C. Park, S. Hirano, 2008, Microstructural characteristics and mechanical properties of Ti-6Al-4V friction stir welds, Materials Science and Engineering A, Vol. 485, pp.448-455.

DOI: 10.1016/j.msea.2007.08.051

Google Scholar

[5] P. Edwards, M. Ramulu, 2009, Effect of Process Conditions on Superplastic Forming Behavior in Titanium 6Al-4V Friction Stir Welds, Science and Technology of Welding and Joining, Vol. 14, No 7, pp.669-680.

DOI: 10.1179/136217109x12464549883330

Google Scholar

[6] D. Sanders, M. Ramulu, P. Edwards, A. Cantrell, 2008, Effect on the surface texture, superplastic forming and fatigue performance of titanium 6Al-4V Friction Stir Welds, AeroMat Conference, Austin, TX, June (2008).

DOI: 10.1007/s11665-010-9614-4

Google Scholar

[7] R. John, K.V. Jata and K. Sadananda, 2003, Residual stress effects on near-threshold fatigue crack growth in friction stir welds in aerospace alloys, International Journal of Fatigue, Vol. 25, pp.939-948.

DOI: 10.1016/j.ijfatigue.2003.08.002

Google Scholar

[8] S. Pasta and A.P. Reyonds, 2008, "Residual stress effects on fatigue crack growth in Ti-6Al-4V friction stir weld, Fatigue & Fracture of Engineering Materials & Structures, Vol 31, pp.569-580.

DOI: 10.1111/j.1460-2695.2008.01258.x

Google Scholar