The Influence of Grain Structure and Texture on Formability and Toughness of Extruded Aluminium Alloys

Article Preview

Abstract:

The main focus in this work is to investigate the effect of crystallographic texture, grain structure and dispersoids on formability and toughness in some industrial 6xxx and 7xxx series alloys. Materials of these alloys showing strong cube textures or β-fibre deformation textures in as extruded condition have been compared with the same alloys processed by rolling and heat treatment to obtain a random texture. It is found that the formability depends on the temper and the texture and that the effect of the latter is path dependent. Materials with a random texture have a significant higher formability in terms of uniform elongation than materials with cube texture when deformed in the W-temper condition. Forming in other deformation modes shows less difference between the cube and random texture. However, a fibrous grain structure with a sharp β-fibre texture shows an anomalous behaviour when deformed in the biaxial deformation regime. Toughness, in terms of Charpy energy and local strains in the necking area, is significantly higher for materials with a cube texture as compared to materials with random textures. This difference is explained by variations in the dispersoid levels, grain structures (size and grain boundary misorientation) and the texture.

You might also be interested in these eBooks

Info:

Periodical:

Materials Science Forum (Volumes 519-521)

Pages:

1421-1428

Citation:

Online since:

July 2006

Export:

Price:

Permissions CCC:

Permissions PLS:

Сopyright:

© 2006 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

[1] T. Furu and H.E. Vatne, Mat. Science Forum, Vol. 273-275 (1998), pp.403-411.

Google Scholar

[2] P.D. Wu, S.R. MacEwen, D.J. Lloyd and K.W. Neale, Materials Science and Engineering A, Volume 364, (2004) pp.182-187.

Google Scholar

[3] S. Fjeldbo, B. Holmedal, O. -G. Lademo, H. Bjerkaas, S. Støren, H.J. Roven, J. Hjelen, O.S. Hopperstad, T. Berstad, K.O. Pedersen, T. Furu, Proceedings of the 8th ESAFORM conference on material forming (2005) pp.209-212.

Google Scholar

[4] F.J. Humphreys, Acta Met., Volume 25, (1977), 1323.

Google Scholar

[5] A. Fjeldly and H.J. Roven, Met. Trans. A, Vol. 31A, (2000) p.669.

Google Scholar

[6] J.M. Dowling and J.W. Martin, Acta Met. , vol. 24A, (1976) pp.1147-1163.

Google Scholar

[7] B.J. Dunwoody, D.M. Moore and A.T. Thomas, J. Inst. Met., Vol. 101 (1973), p.172.

Google Scholar

[8] O. Lohne and O.J. Naess, Proc. 5th Int. Conf. Strength of Metals and Alloys, Aachen (1979), pp.781-788.

Google Scholar

[9] K.O. Pedersen and T. Furu, Paper to be published.

Google Scholar