On development of hypoeutectic aluminium–silicon powder metallurgy alloy

Abstract

Powder metallurgy allows for the rapid, automated and efficient production of many different types of automotive components. However, a drawback is the limited selection of readily available light alloy blends. Owing to the wide spread use of aluminium–silicon casting alloys for existing components it is logical to develop aluminium–silicon PM options. Therefore, an experimental hypoeutectic aluminium–silicon alloy was chosen for study and an optimum processing route developed. Tests were performed to determine the green strength and density as a function of compaction pressure. Sintering conditions were optimised based on sintered density, hardness and dimensional changes. Metallography, differential scanning calorimetry and energy dispersive X-ray spectroscopy analysis provided insight into post-sinter furnace cooling and heat treatment parameters. An appropriate T6 heat treatment was developed and samples were tested in tension. The alloy was able to achieve a high sintered density approaching 98% and a yield strength of 232 MPa under the T6 condition.

Keywords

Aluminium Powder metallurgy Sintering Compaction Aluminium–silicon Processing

Get full access to this article

View all access options for this article.

References

German MR : ‘Powder metallurgy & particulate materials processing’; 2005, Princeton, NJ, Metal Powder Industries Federation.

Pease

, West

: ‘Fundamentals of powder metallurgy’; 2002, Princeton, NJ, Metal Powder Industries Federation.

Smith

: ‘Structure and properties of engineering alloys’, 2nd edn; 1993, New York, McGraw-Hill, Inc.

Polmear

: ‘Light alloys: from traditional alloys to nanocrystals’, 4th edn; 2006, Oxford, Elsevier/Butterworth-Heinemann.

Kuroishi

: ‘High strength, high wear resistance aluminium–silicon PM alloys’, Met. Powder Rep., 1985, 40, (11), 642.

Perrot

: ‘Engine cylinder liners in high silicon aluminum alloy produced by powder metallurgy’, Revue L'aluminium, 1979, (482), 129.

Yilmaz

: ‘Production of hypereutectic Al-Si alloys by P/M route’, Mater. Sci. Forum, 1996, 217, (3), 1853.

MPIF : ‘Standard test methods for powders and powder metallurgy products’, 2008, Princeton, NJ, Metal Powder Industries Federation.

Heard

, Donaldson

, Bishop

: ‘Metallurgical assessment of a hypereutectic aluminium–silicon P/M alloy’, J. Mater. Process. Technol., 2009, 209, 5902.

10.

Bishop

, Hofmann

, Couchman

, “Properties and Attributes of Commercially Availiable AC2014-Type Aluminium P/M Alloys”, Advances in Powder Metallurgy and Particulate Materials, ed by H. Ferguson and DOI Whychell, MPIF, 1, Part 12, (2000), 87–100.

11.

Hennessey

, Caley

, Kipouros

, Bishop

: ‘Development of a PM aluminum alloy: effect of post-sinter cooling conditions’, Int. J. Powder Metall., 2006, 42, (6), 39.

12.

Baker

, ed (ed.): ‘Alloy phase diagrams’; 1992, Materials Park, OH, ASM International.

13.

Villars

, Prince

, Okamoto

: ‘Handbook of ternary alloy phase diagrams’; 1995, Materials Park, OH, ASM International.

14.

Massalski

, Okamoto

, ASM International (eds.): ‘Binary alloy phase diagrams’, 2nd edn; 1990, Materials Park, OH, ASM International.

15.

Starink

: ‘Analysis of aluminium based alloys by calorimetry: quantitative analysis of reactions and reaction kinetics’, Int. Mater. Rev., 2004, 49, (3), 191.

16.

Abis

: ‘Study of ageing in an AlCuMgZn foundry alloy’, Mater. Sci. Eng. A, 1996, A214, (1), 153.

17.

Heard

: ‘Methods to improve density and mechanical properties of a commercial hypereutectic aluminum–silicon powder metallurgy alloy’, Master's dissertation, Dalhousie University, Halifax, Canada, 2008.