Submicrocristalline Structure and Dynamic Recovery of Cold Flowformed ELI Grade Ti-6Al-4V

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Flowforming is a means to produce seamless tubes by plastic deformation at room temperature. It consists in reducing the thickness of a tubular part mounted on a mandrel by deforming it using several rollers translating along the tube axis, while the tube is rotating along its axis. Thanks to the high compressive stresses, and to the incremental nature of the deformation process, flowforming can lead to a high thickness reduction and thus to high elongation of the deformed tubes. Ti-6Al-4V (Extra Low Interstitial grade) tubes have been deformed by cold flowforming, with a thickness reduction ratio higher than 60%, and their microstructures have been investigated using light optical microscopy (LOM), scanning electron microscopy (SEM) and electron backscattered diffraction (EBSD). Based on EBSD data, a post-processing analysis has been performed in order to study the texture of the flowformed parts. Optical Microscopy showed that the material could be deformed without displaying flow instability such as adiabatic shear banding, despite the fact that it has been processes out of the stable processing maps (high strain rate and low temperature). It also evidenced a major deformation along the tube axis accompanied with a slight twist due to torsion stress. EBSD analysis indicated the occurrence of continuous dynamic recrystallization, which is rarely reported in the α-β domain of such alloys. The recovery/ recrystallization effects resulted in a submicrocrystalline equiaxed structure, which is consistent with that previously reported for Ti-6Al-4V subjected to severe plastic deformation (SPD). The texture of the hexagonal α-phase appeared to be similar to that obtained on extruded Ti-6Al-4V, with a basal component perpendicular to the tube axis.

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Periodical:

Key Engineering Materials (Volumes 554-557)

Edited by:

Ricardo Alves de Sousa and Robertt Valente

Pages:

157-168

Citation:

D. Depriester and E. Massoni, "Submicrocristalline Structure and Dynamic Recovery of Cold Flowformed ELI Grade Ti-6Al-4V", Key Engineering Materials, Vols. 554-557, pp. 157-168, 2013

Online since:

June 2013

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$38.00

[1] Welsch, G. and Bunk, W. May 1982 Metall. Mater. Trans. A 13(5), 889-899.

[2] Zaefferer, S. March 2003 Mat. Sci. Eng. A 344(1-2), 20-30.

[3] Prasad, Y., Seshacharyulu, T., Medeiros, S., and Frazier, W. (2001) J. Mater. Process. Technol. 108(3), 320-327.

[4] Preuss, M., daFonseca, J. Q., Allen, V., Prakash, D. G. L., and Daymond, M. R. July 2010 J. of Strain Anal. for Eng. Des. 45(5), 377 -390.

[5] Santhanam, A. T. and Reed-Hill, R. E. September 1971 Met. Trans. 2, 2619-2622.

[6] Bozzolo, N., Dewobroto, N., Wenk, H. R., and Wagner, F. December 2006 J. of Mat. Sci. 42(7), 2405-2416.

[7] Williams, J., Baggerly, R., and Paton, N. (2002) Metall. Mater. Trans. A 33, 837-850 10. 1007/s11661-002-1016-2.

[8] Seshacharyulu, T., Medeiros, S., Frazier, W., and Prasad, Y. February 2002 Mat. Sci. Eng. A 325(12), 112-125.

[9] Gungor, M. N., Ucok, I., Kramer, L. S., Dong, H., Martin, N. R., and Tack, W. T. November 2005 Mat. Sci. Eng. A 410-411(0), 369-374.

[10] Seshacharyulu, T., Medeiros, S., Morgan, J., Malas, J., Frazier, W., and Prasad, Y. (2000) Mat. Sci. Eng. A 279(12), 289-299.

[11] Salishchev, G., Galeyev, R., Valiakhmetov, O., Safiullin, R., Lutfullin, R., Senkov, O., Froes, F., and Kaibyshev, O. October 2001 J. Mater. Process. Technol. 116(2-3), 265-268.

DOI: https://doi.org/10.1016/s0924-0136(01)01037-8

[12] Yoshimura, H. and Nakahigashi, J. July 2002 Int J. of Hydrog. Energ. 27(7-8), 769-774.

[13] Salishchev, G. A., Valiakhmetov, O. R., and Galeyev, R. M. (1993) J. of Mat. Sci. 28, 2898- 2902.

[14] Ko, Y., Lee, C., Shin, D., and Semiatin, S. (2006) Metall. Mater. Trans. A 37, 381-391 10. 1007/s11661-006-0008-z.

[15] Ko, Y. G., Lee, C. S., and Shin, D. H. June 2008 Scripta Mater. 58(12), 1094-1097.

[16] Zherebtsov, S., Murzinova, M., Salishchev, G., and Semiatin, S. June 2011 Acta Mater. 59(10), 4138-4150.

DOI: https://doi.org/10.1016/j.actamat.2011.03.037

[17] Chang, S., Huang, C., Yu, S., Chang, Y., Han, W., Shieh, T., Chung, H., Yao, H., Shyu, G., Hou, H., Wang, C., and Wang, W. August 1998 J. Mater. Process. Technol. 80-81(0), 676-682.

DOI: https://doi.org/10.1016/s0924-0136(98)00174-5

[18] Davidson, M. J., Balasubramanian, K., and Tagore, G. May 2008 J. Mater. Process. Technol. 200(1-3), 283-287.

[19] Roy,M., Klassen, R., andWood, J. January 2009 J. Mater. Process. Technol. 209(2), 1018-1025.

[20] Haghshenas, M., Jhaver, M., Klassen, R., and Wood, J. June 2011 Mat. and Des. 32(6), 3629- 3636.

[21] Gungor, M. N., Kramer, L. S., Ucok, I., Dong, H., and Tack, W. T. (2007).

[22] Salishchev, G., Zerebtsov, S., Mironov, S., and Semiatin, S. (2004).

[23] Humphreys, F. and Hatherly, M. (2004) Chapter 13 - hot deformation and dynamic restoration In Recrystallization and Related Annealing Phenomena (Second Edition) p.415 - V Elsevier Oxford second edition edition.

DOI: https://doi.org/10.1016/b978-008044164-1/50017-7

[24] Yang, Y. and Wang, B. August 2006 Mat. Lett. 60(1718), 2198-2202.

[25] Yang, D., An, Y., Cizek, P., and Hodgson, P. May 2011 Mat. Sci. Eng. A 528(12), 3990-3997.

[26] Yapici, G. G., Karaman, I., and Luo, Z. -P. August 2006 Acta Mater. 54(14), 3755-3771.

[27] Coghe, F., Tirry, W., Rabet, L., Schryvers, D., and Van Houtte, P. March 2012 Mat. Sci. Eng. A 537(0), 1-10.

[28] Ravi Kumar, N., Blandin, J., Desrayaud, C., Montheillet, F., and Sury, M. October 2003 Mat. Sci. Eng. A 359(12), 150-157.

[29] Yang, X., Miura, H., and Sakai, T. (2003) Mat. Trans. 44(1), 197203.