Dispersoid strengthening of Al–Cu–Mg P/M alloy utilising transition metal additions

Abstract

The objective of this research was to devise a means by which dispersoid forming transition metals could be incorporated into press and sinter aluminium powder metallurgy (P/M) alloys. Additions of iron and nickel were explored in this context added as either admixed elemental powders or prealloyed additions into the base aluminium powder. Utilising an Al–2·3Cu–1·6Mg–0·2Sn composition as the base system, elemental additions imparted coarse aluminide phases within the sintered microstructure and diminished the general sintering response of the alloy. The resultant tensile properties of these materials were inferior to those of the unmodified base alloy. Prealloying was much more effective. Using this approach, highly refined distributions of aluminides were achieved without any adverse effects on the compaction or sintering response of the base alloy. A prealloyed addition of 1 wt-% iron was the most effective of those considered as it imparted tangible gains in yield strength and ultimate tensile strength (UTS) to the base alloy.

Keywords:

• Aluminium powder metallurgy
• Transition metals
• Dispersoid strengthening
• Iron
• Nickel
• Aluminides
• Prealloying

Acknowledgements

The authors would like to acknowledge funding assistance provided by the Natural Sciences and Engineering Research Council of Canada and the Auto21 Networks of Centers of Excellence via grant no. C202-CPM. The provision of most powdered metals by Dr B. Mais and Mr J. Gradl at Ecka Granules is also graciously acknowledged as is the technical support provided by Mr D. Grijm.