The Effect of Grain Refinement and Cooling Rate on the Hot Tearing of Wrought Aluminium Alloys

Article Preview

Abstract:

Using modifications to the Rappaz-Drezet-Gremaud hot tearing model, and using empirical equations developed for grain size and dendrite arm spacing (DAS) on the addition of grain refiner for a range of cooling rates, the effect of grain refinement and cooling rate on hot tearing susceptibility has been analysed. It was found that grain refinement decreased the grain size and made the grain morphology more globular. Therefore refining the grain size of an equiaxed dendritic grain decreased the hot tearing susceptibility. However, when the alloy was grain refined such that globular grain morphologies where obtained, further grain refinement increased the hot tearing susceptibility. Increasing the cooling decreased the grain size and made the grain morphology more dendritic and therefore increased the likelihood of hot tearing. The effect was particularly strong for equiaxed dendritic grain morphologies; hence grain refinement is increasingly important at high cooling rates to obtain more globular grain morphologies to reduce the hot tearing susceptibility.

You might also be interested in these eBooks

Info:

Periodical:

Materials Science Forum (Volumes 519-521)

Pages:

1675-1680

Citation:

Online since:

July 2006

Export:

Price:

[1] J.F. Grandfield, C.J. Davidson, and J.A. Taylor: Light Metals 2001. (2001): The Metals, Minerals and Materials Society: p.911.

Google Scholar

[2] M. Rappaz, J. -M. Drezet, and M. Gremaud: Metall. Mater. Trans. A, Vol. 30A, (1999), p.449.

Google Scholar

[3] M.A. Easton, et al.: Materials Forum, Vol. 28, (2004), p.224.

Google Scholar

[4] J.F. Grandfield, et al.: 2nd International light metals technology conference. (2005). St. Wolfgang, Austria: p.75.

Google Scholar

[5] M. M'Hamdi, et al.: Aluminium, Vol. 78, (2002), p.847.

Google Scholar

[6] M.A. Easton and D.H. StJohn: Light Metals 2001. (2001): The Minerals, Metals and Materials Society, Warrendale, Pensylvania: p.927.

Google Scholar

[7] M.A. Easton and D.H. StJohn: Metall. Mater. Trans. A, Vol. 36A, (2005), p. (1911).

Google Scholar

[8] M.A. Easton and D.H. StJohn: To be published.

Google Scholar

[9] M.C. Flemings, T.Z. Kattamis, and B.P. Bardes: AFS Trans., Vol. 99, (1991), p.501.

Google Scholar

[10] W. Kurz and D. Fisher, Fundamentals of solidification, 4th edition. (1998): Trans Tech Publications, Switzerland.

Google Scholar

[11] D. Warrington and D.G. McCartney: Cast Metals, Vol. 3, (1991), p.202.

Google Scholar

[12] J.M.V. Quaresma, C.A. Santos, and A. Garcia: Metall. Mater. Trans. A, Vol. 31A, (2000), p.3167.

Google Scholar

[13] D.J. Lahaie and M. Bouchard: Metall. Mater. Trans B, Vol. 32B, (2001), p.697.

Google Scholar

[14] Ø. Nielsen, B. Appolaire, H. Combeau, and A. Mo: Metall. Mater. Trans. A, Vol. 32A, (2001), p. (2049).

Google Scholar