Rev.Adv.Mater.Sci.(RAMS)
No 1, Vol. 6, 2004, pages 28-32

NANOSTRUCTURED HIGH STRENGTH Mg-5%Al-x%Nd ALLOYS PREPARED BY MECHANICAL ALLOYING

L. Lu1, M.O. Lai1, C. Yan2 and L. Ye2

1 Department of Mechanical Engineering, National University of Singapore,
Singapore 117576, Singapore
2 Department of Aeronautic, Mechanical and Mechatronic Engineering University
of Sydney, NSW 2006, Australia

Abstract

Nanostructured Mg-5%Al-x%Nd (x = 0.5, 1 and 5 wt.%) alloys were prepared by mechanical alloying. Microstructural characterization revealed average crystalline size to be about 30 nm after mechanical alloying while it increased to about 90 nm after sintering and extrusion. Mechanical properties showed increase in 0.2% yield stress, ultimate tensile strength and ductility after 20 h of mechanical alloying. The increase in yield stress and ultimate tensile strength was attributed to reduction in grain size as well as to the enhanced diffusion after mechanical activation. Although ultra high yield stress was observed from the specimen with 5%Nd, its ductility was reduced to about 1.6%.

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