An Investigation of Novel Spraycast Al-Mg-Li-Zr-(Sc) Alloys

S.C. Hogg; I.G. Palmer; Patrick S. Grant

doi:10.4028/www.scientific.net/MSF.519-521.1629

Paper Titles

Influence of Concurrent Precipitation on the Nucleation Kinetics during Recrystallisation in AA3003
p.1605

Deformation and Recrystallization Behaviour of a Homogenised and a Heterogenised Al-Mg-Si Alloy
p.1611

Changes in Grain Size Distribution of a Submicron Grained Al-Sc Alloy during High Temperature Annealing
p.1617

Effect of Mn Intermetallic Particle on Microstructure Development of P/M Al-Zn-Mg-Cu-Mn Alloy
p.1623

An Investigation of Novel Spraycast Al-Mg-Li-Zr-(Sc) Alloys
p.1629

Recrystallization Behaviour in Twin-Roll Continuous Cast Al-Fe-Ni Alloy
p.1635

A Comparative Study on the Softening Behaviour of Cold Rolled Ingot and Continuous Cast AA5754
p.1641

Precipitation and Recrystallization in an Al-Mg-Sc Alloy
p.1647

Recovery of Tensile Properties of AA5182 after Cold Rolling
p.1653

HomeMaterials Science ForumMaterials Science Forum Vols. 519-521An Investigation of Novel Spraycast...

An Investigation of Novel Spraycast Al-Mg-Li-Zr-(Sc) Alloys

Abstract:

This work describes the microstructure and properties of a range of Al-(4-6)Mg- (1.2-1.6)Li-(0.3-0.4)Zr-(0-0.2)Sc alloys produced at Oxford University by spraycasting. Follow- ing hot isostatic pressing of the as-spraycast billets to close any porosity and to precipitate a ¯ne, coherent dispersoid population, forging to a true strain of 1 at 250 and 400±C led to a substantial re¯nement of the microstructure with grain sizes in the range 0.8 to 5¹m. A large intra-granular orientation gradient with distance measured using EBSD showed that at 250±C, partial dynamic recrystallisation by progressive lattice rotation led to a `necklace' structure of very ¯ne grains surrounding larger deformed grains. At 400±C, dynamic recrystallisation oc- curred by nucleation of new grains at prior grain boundaries and triple points. The strength of as-forged alloys was 200-350MPa and the high ductilities of up to 30% rendered the alloys amenable to post-forging cold work. A proof strength of 460MPa with 9.5% elongation was achieved in a non-heat-treatable spraycast Al-6Mg-1.3Li-0.4Zr alloy, matching the best prop- erties of similar mechanically alloyed AA5091, and exceeding the properties of AA7010-T74. The as-forged alloys showed excellent thermal stability up to » 0.9Tm, with no abnormal grain growth and grain size stagnation due to Zener pinning. Finally, strain rate sensitivity testing revealed the potential for superplasticity at 400 and 500±C and strain rates of 0.001-0.05s¡1.

You might also be interested in these eBooks

View Preview

Info:

Periodical:

Materials Science Forum (Volumes 519-521)

Pages:

1629-1634

DOI:

https://doi.org/10.4028/www.scientific.net/MSF.519-521.1629

Citation:

Cite this paper

Online since:

July 2006

Authors:

S.C. Hogg, I.G. Palmer, Patrick S. Grant

Keywords:

Al-Mg-Li, Dynamic Recrystallization (DRX), Electron Backscatter Diffraction (EBSD), Spraycasting, Zener Pinning

Export:

RIS, BibTeX

Price:

Permissions:

Request Permissions

References

[1] C.J. Peel, B. Evans, C.A. Baker, D.A. Bennett, P.J. Gregson and H. M Flower: Proc Al-Li II, TMS-AIME, 1983, p.363.

Google Scholar

[2] S.C. Hogg, I.G. Palmer and P.S. Grant: Mat. Forum Vol. 28 (2004) p.325 (Proc ICAA9).

Google Scholar

[3] I.G. Palmer and J. White: Proc. Int Conf. Sprayforming 4, Baltimore, (1999).

Google Scholar

[4] M. R. Drury and F. J. Humphreys: Acta Met. Vol. 34 (1986) p.2259.

Google Scholar

[5] S. C. Hogg, I.G. Palmer and P.S. Grant: Control of Microstructure in a Spraycast Al-Mg-Li-Zr Alloy, submitted to Acta Mater. Jan (2006).

DOI: 10.1016/j.actamat.2006.10.057

Google Scholar

[6] W.J. Vine, P.D. Pitcher and A.D. Tarrant: Mater. Sci. Tech. Vol. 17 (2001) p.802.

Google Scholar

[7] S.J. Hales, T.R. McNelley and I.G. Munro: Scripta Met. Vol. 23 (1989) p.967.

Google Scholar

[8] R.D. Schelleng, G.A.J. Hack and J.H. Weber: Lightweight Al-Mg-Li-O-C Forging Alloy, in Proc Int. Conf. on Advanced Aluminium and Magnesium Alloys, Amsterdam, June 1990, p.289.

DOI: 10.1016/0026-0657(90)90941-9

Google Scholar

[9] M. Ferry, N.E. Hamilton and F.J. Humphreys: Acta Mater. Vol. 53 (2005) p.1097.

Google Scholar