Nano-Scale Clusters Formed in the Early Stage of Phase Decomposition of Al-Mg-Si Alloys

Abstract:

Article Preview

The formation of nano-scale clusters (nanoclusters) prior to the precipitation of the strengthening b” phase significantly influences two-step aging behavior of Al-Mg-Si alloys. In this work, the existence of two kinds of nanoclusters has been verified in the early stage of phase decomposition by differential scanning calorimetry (DSC) and three-dimensional atom probe (3DAP). Pre-aging treatment at 373K before natural aging was also found to form preferentially one of the two nanoclusters, resulting in the remarkable restoration of age-hardenability at paint-bake temperatures. Such microstructural control by means of optimized heat-treatments; i.e. nanocluster assist processing (NCAP), possesses great potential for enabling Al-Mg-Si alloys to be used more widely as a body-sheet material of automobiles.

Info:

Periodical:

Materials Science Forum (Volumes 475-479)

Main Theme:

Edited by:

Z.Y. Zhong, H. Saka, T.H. Kim, E.A. Holm, Y.F. Han and X.S. Xie

Pages:

357-360

Citation:

S. Hirosawa and T. Sato, "Nano-Scale Clusters Formed in the Early Stage of Phase Decomposition of Al-Mg-Si Alloys", Materials Science Forum, Vols. 475-479, pp. 357-360, 2005

Online since:

January 2005

Export:

Price:

$41.00

[1] K. Yamada, T. Sato and A. Kamio: Mater. Sci. Forum Vols. 331-337 (2000), p.669.

[2] K. Yamada, T. Sato and A. Kamio: J. Japan Inst. of Light Metals 51 (2001), p.215.

[3] F. Danoix, M.K. Miller and A. Bigot: Ultramicroscopy 89 (2001), p.177.

[4] M. Takeda, F. Ohkubo, T. Shirai and K. Fukui: Mater. Sci. Forum Vols. 217-222 (1996), p.815.

[5] M. Takeda, F. Ohkubo, T. Shirai and K. Fukui: J. Mater. Sci. 33 (1998), p.2385.

[6] G.A. Edwards, K. Stiller, G.L. Dunlop and M.J. Couper: Acta mater. 46 (1998), p.3893.

[7] M. Murayama, K. Hono, M. Saga and M. Kikuchi: Mat. Sci. Eng. A250 (1998), p.127.

[8] M. Murayama and K. Hono: Acta mater. 47 (1999), p.1537.

[9] D. Vaumousse, A. Cerezo and P.J. Warren: Ultramicroscopy 95 (2003), p.215.

[10] T. Sato, S. Hirosawa, K. Hirose and T. Maeguchi: Metall. Mater. Trans. 34A (2003).