Abstract
This article reports on a remarkable natural ageing response observed for the first time in this work in Mg–Zn-based alloys. In these alloys, hardness in the naturally aged condition, generally, almost equals that in the artificially aged condition. The time to maximal hardness in the naturally aged condition can be dramatically reduced from several months needed for a binary Mg–Zn alloy, to a practical duration of a few weeks when some additional alloying elements that act as accelerants are added. Examples of such elements presented here are Cu and Ti. Strengthening in the naturally aged condition of these alloys is achieved through the formation of a very high density of Guinier-Preston (GP) zone-type precipitates. Both Cu and Ti also enhance the artificial ageing response by increasing the number density of the strengthening precipitates. Unlike Cu, Ti is not detrimental to the corrosion resistance and the current results indicate that it also has a very pronounced grain-refining effect on the Mg–Zn-based alloys.
Similar content being viewed by others
References
Lorimer GW (1986) Magnesium technology. Institute of Metals, London, p 47
Clark JB (1965) Acta Metall 13:1281
Gao X, Nie JF (2007) Scripta Mater 56:645
King JF, Unsworth W (1980) US Patent 4239535
Unsworth V (1987) Light Metal Age 8:10
Mima G, Tanaka Y (1971) Trans JIM 12:71
Takahashi T, Kojima Y, Takahashi K (1973) Jpn J Inst Light Metals 23:376
Polmear IJ (1995) Light alloys: metallurgy of the light metals, 3rd edn. Arnold, London, p 204
ASM Specialty Handbook (1998) Magnesium and magnesium alloys. ASM International, p 27
Hansen M (1958) Constitution of binary alloys, 2nd edn., written in cooperation with Anderko K. McGraw-Hill Book Co., New York, p 924
Wei LY, Dunlop GL, Westengen GL (1995) Metall Mater Trans A 26A:1947
Kelly A, Nicholson RB (1963) Prog Mater Sci 10:151
Lomer WM (1958) Inst Metals Monogr Rep Ser 23:79
Embury JD, Nicholson RB (1965) Acta Metall 13:403
Acknowledgement
The author wishes to acknowledge the financial support of the Japanese Society for the Promotion of Science (JSPS) in the form of a JSPS Postdoctoral Fellowship.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Buha, J. Natural ageing in magnesium alloys and alloying with Ti. J Mater Sci 43, 1220–1227 (2008). https://doi.org/10.1007/s10853-007-2250-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10853-007-2250-1