Microstructure and Mechanical Properties of Al-Li Alloy 2397-T87 Rolled Plate

Abstract:

The microstructure, tensile property and fracture toughness of Al-Li alloy 2397-T87 rolled plate were investigated by optical microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, tensile and plane-strain fracture toughness tests. The results show that a pronounced texture variation through the plate thickness was found. Near the surface, Goss texture dominated. While in the center of the plate, typical β fiber texture and a scattering of cube texture were observed. And the subsurface layer exhibited a very weak texture. From the center to the subsurface, the fraction of β fiber texture and cube texture decreased. In contrast, the fraction of shear type texture reaching the maximum in subsurface layer increased. The tensile properties in different layers along the thickness direction were inhomogeneous. The strengths near the surface were lower than those in the center. And the through-thickness strength properties variation in the rolling direction was more remarkable than that in the long transverse direction. In the same thickness layer, the fracture toughness and the strengths were anisotropic. The strengths in the rolling direction were higher than those in the long transverse direction and the short transverse direction, and the strengths in the short transverse direction were the lowest. The fracture toughness in L-T orientation was the highest, followed by that in T-L orientation, and the fracture toughness in S-L orientation was the lowest.

• Periodical: Materials Science Forum (Volume 788)
• Pages: 249-257
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.788.249
• Online since: April 2014
• Authors: Chun Ping Fan*, Zi Qiao Zheng, Min Jia, Ji Fa Zhong, Bin Cheng
• Keywords: Al-Li Alloy, Fracture Toughness, Mechanical Property, Texture

References

[1] R. Grimes, A.J. Cornish, and W. S. Miller, Aluminum-lithium based alloys for aerospace application, Met. Mater. 1 (1985) 357-366.

[2] C.J. Williams, A.Jr. Starke, Progress in structural materials for aerospace systems , Acta Mater. 51(2003)5775-5799.

[3] V. Guillaumin, Aluminum-lithium alloys in airbus airframes, J. Aerospace Eng. 8(2005) 158-164.

[4] E.S. Balmuth, Application of Aluminum Alloy 2297 in Fighter Aircraft Structures, in: Proceedings from LiMat, Pusan, Korea, 2001, pp.6-10.

[5] S.J. Yang, Z. Lu, S.L. Dai, Y.F. Han, M.G. Yan, A new high strength and high tolerance-resistance Al-Li alloy, Trans. Nonferrous Met. Soc. China. 16(2006) 1649-1654.

[6] B.P. Mao, J.P. Li, J. Shen, Effect of Thermo-mechanical Heat Treatment on Microstructure and Mechanical Property of 2197 Al-Li alloy, Adv. Mater. Res. 284-286(2011)1621-1625.

DOI: 10.4028/www.scientific.net/amr.284-286.1621

[7] J. Jabra, M. Romios, J. Lai, E. lee, M. Setiawan, The Effect of Thermal Exposure on the Mechanical Properties of 2099-T6 Die Forgings, 2099-T83Extrusions, 7075-T7651 Plate, 7085-T7452 Die Forgings, 7085-T7651 Plate, and 2397-T87 Plate Aluminum Alloys, J. Mater. Eng. Perform. 15 (2006) 601-607.

DOI: 10.1361/105994906x136142

[8] J.G. Tang, X.M. Zhang, Y.L. Deng, X.Y. Du, Z.Y. Chen, Texture decomposition with particle swarm optimization method, Comput. Mater. Sci. 38 (2006) 395-399.

DOI: 10.1016/j.commatsci.2005.09.015

[9] J. Chen, L. Zhen, W. Shao, S. Dai, Y. Cui, Through-thickness texture gradient in AA 7055 aluminum alloy. Mater. Lett. 62 (2008) 88-90.

DOI: 10.1016/j.matlet.2007.04.074

[10] O. Engler, An EBSD local texture study on the nucleation of recrystallization at shear bands in the alloy Al-3% Mg, Scripta mater. 44 (2001) 229-236.

DOI: 10.1016/s1359-6462(00)00597-2

[11] O. Engler, C. Tomé, M.Y. Huh, A study of through-thickness texture gradients in rolled sheets, Metall. Mater. Trans. A . 31 (2000) 2299-2315.

DOI: 10.1007/s11661-000-0146-7

[12] T. Kamijo, S. Kataoka, H. Inagaki, Nucleation and growth of cube-oriented recrystallized grains in an aluminum single crystal of an s-orientation, Acta Metall. Mater. 41 (1993) 1713-1720

DOI: 10.1016/0956-7151(93)90190-4

[13] S.H. Hong, H.T. Jeong, C.H. Choi, D. Lee, Deformation and recrystallization textures of surface layer of copper sheet, Mater. Sci. Eng. A. 229 (1997) 174-181.

DOI: 10.1016/s0921-5093(96)10818-2

[14] C.H. Choi, J.W. Kwon, K.H. Oh, D.N. Lee, Analysis of deformation texture inhomogeneity and stability condition of shear components in fcc metals, Acta Mater. 45 (1997) 5119-5128.

DOI: 10.1016/s1359-6454(97)00169-9

[15] H. Vatne, R. Shahani, E. Nes, Deformation of cube-oriented grains and formation of recrystallized cube grains in a hot deformed commercial AlMgMn aluminium alloy, Acta Mater. 44 (1996) 4447-4462.

DOI: 10.1016/1359-6454(96)00077-8

[16] M. Starink, S. Wang, A model for the yield strength of overaged Al–Zn–Mg–Cu alloys, Acta Mater. 51 (2003) 5131-5150.

DOI: 10.1016/s1359-6454(03)00363-x

[17] A. Vasudevan, W. Fricke, R. Malcolm, R. Bucci, M. Przystupa, F. Barlat, On through thickness crystallographic texture gradient in Al-Li-Cu-Zr alloy, Metall. Mater. Trans. A. 19(1988) 731-732.

DOI: 10.1007/bf02649289

[18] D. Chakrabarti, H. Weiland, B. Cheney, J.T. Staley, Through thickness property variations in 7050 plate, Mater. Sci. Forum. 217-222(1996) 1085-1090.

DOI: 10.4028/www.scientific.net/msf.217-222.1085

[19] Z.H. Li, B.Q. Xiong, Y.A. Zhang, Investigation on strength, toughness and microstructure of an Al-Zn-Mg-Cu alloy prestretched thick plate in various ageing tempers, J. Mater. Process. Tech. 209 (2008) 2021-2027.

DOI: 10.1016/j.jmatprotec.2008.04.052

[20] D. Dumont, A. Deschamps, Y. Brechet, On the relationship between microstructu -re, strength and toughness in AA7050 aluminum alloy, Mater. Sci. Eng. A. 356(2003) 326-336.

DOI: 10.1016/s0921-5093(03)00145-x

[21] R.J. Rioja, Fabrication methods to manufacture isotropic Al-Li alloys and products for space and aerospace applications, Mater. Sci. Eng. A. 257(1998) 100-107.

DOI: 10.1016/s0921-5093(98)00827-2

[22] K.T. Venkateswara, R.O. Ritchie, Mechanical properties of Al-Li alloys Part 1Fracure toughness and microstructure, Mater. Sci. Tech. 70(1989) 882-895.

DOI: 10.1179/mst.1989.5.9.882