Spray Forming of AZ91 Magnesium Alloys with and without Si Addition

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Abstract:

ray forming was employed to refine the microstructures of AZ91 and AZ91-3.34wt%Si Mg alloys during solidification by means of rapid solidification generated at atomization and droplet flight stages. The process parameters of spray forming were varied to reduce the porosity level and improve the morphology of the billet preforms. As-spray-formed microstructures were characterized using OM, SEM/EDS, and XRD, which were compared with as-cast microstructures. The significant differences of grains, Mg2Si and Mg17Al12 in morphology and in size between as-spray-fromed and as-cast materials are mainly due to fast cooling and solidification rates of spray forming process. Supersaturated matrix is found in as-spray-formed materials due to rapid solidification generated by spray forming. Overall, spray-formed materials are shown to have four characteristics, which are much finer microstructures, uniformly distributed phases, equiaxed-shaped phases, and supersaturated matrix.

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Periodical:

Materials Science Forum (Volumes 475-479)

Pages:

2789-2794

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Online since:

January 2005

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[1] M. Mabuchi and K. Higashi: Acta Materialia Vol. 44, no. 11, (1996), p.4611.

Google Scholar

[2] G.H. Li, H.S. Gill, R.A. Varin: Metallurgical transactions A Vol. 24A, (1993), p.2383.

Google Scholar

[3] N. Raghunahan, T. Sheppard: Materials Science and Technology Vol. 6, (1990), p.629.

Google Scholar

[4] N.J. Grant: Progress in Material Science Vol. 39 (1995), p.497.

Google Scholar

[5] [ M. De Sanctis: Materials Science and Engineering Vol. A141 (1991), p.103.

Google Scholar

[6] J.F. Faure, G.J. Nussbaum, and G. Regazzoni: Process for obtaining magnesium alloys by spray forming deposition US Patent 5073207, 17. December, (1991).

Google Scholar

[7] T. Elbert, F. Moll, K.U. Kainer: Powder Metallurgy Vol. 40, No. 2 (1997), p.126.

Google Scholar

[8] E.J. Lavernia, J. Baram, E. Guitierrez: Materials Science and Engineering Vol. A132 (1991), p.119.

Google Scholar

[9] C.Y. Chen and Chi Y.A. Tsao: Materials Science Forum Vol. 426, (2003), p.429.

Google Scholar