Title: Influence of heat treatment on the microstructures and mechanical properties of squeeze cast AlSi9Cu3 alloys

Authors: Henda Barhoumi; Slim Souissi; Mohamed Ben Amar; Foued Elhalouani

Addresses: Faculty of Sciences of Sfax (FSS), University of Sfax, B.P. 802-3038, Tunisia ' National Engineering School of Sfax (ENIS), University of Sfax, B.P. 599-3038, Tunisia ' National Engineering School of Sfax (ENIS), University of Sfax, B.P. 599-3038, Tunisia ' National Engineering School of Sfax (ENIS), University of Sfax, B.P. 599-3038, Tunisia

Abstract: The AlSi9Cu3 alloy was prepared by gravity die casting and squeeze casting. This alloy has a good castability, excellent machinability, medium strength and low specific weight. Various test techniques, including optical microscopy, scanning electron microscope, X-ray diffraction, tensile test and hardness were used to examine the effect of pressure levels and T6 heat treatment on the microstructure and mechanical properties of Al9Si3Cu alloy produced by gravity and squeeze casting process. The experimental results showed that this alloy contained α-matrix, eutectic silicon and other Fe- and Cu-rich phases with different morphology. Furthermore, the applied pressure refines the microstructure, improves the tensile properties and increases the hardness Vickers. It was found that a T6 heat treatment was applied, spheroidised eutectic Si particles and fragmented β-phase particles were formed and the mechanical properties were improved.

Keywords: mechanical properties; microstructure; T6 heat treatment; pressure; SDAS; secondary dendrite arm spacing; AlSi9Cu3; aluminium alloys; squeeze casting; gravity die casting; tensile testing; hardness.

DOI: 10.1504/IJMMP.2015.074999

International Journal of Microstructure and Materials Properties, 2015 Vol.10 No.5/6, pp.472 - 487

Received: 31 Oct 2015
Accepted: 28 Dec 2015

Published online: 28 Feb 2016 *

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