Chemical and Materials Engineering Vol. 2(1), pp. 9 - 13
DOI: 10.13189/cme.2014.020102
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The Effects of Ni on Tensile Properties of Al-6Si-0.5Mg Cast Alloys during Precipitation Hardening


A. Hossain *, A. S. W. Kurny
Bangladesh University of Engineering and Technology, Department of Materials and Metallurgical Engineering, Dhaka 1000, Bangladesh

ABSTRACT

The microstructure, tensile properties and fracture behavior of the Al-6Si-0.5Mg and Al-6Si-0.5Mg-2Ni cast alloys were investigated and the results showed that the Mg2Si, Al3Ni and Si hard particles produced by precipitation hardening have great effects. The homogenized (24hr at 500℃) and solutionized (2hr at 540℃) cast alloys were subjected to ageing treatment from room temperature to 300℃. The yield strength and fracture strength of the alloys increased with the ageing temperature and maximum at peakaged condition (1hr at 225℃) where as ductility and impact toughness decreased with ageing temperature reaching the minimum at the peakaged condition. The properties of Ni content and Ni free Al-6Si-0.5Mg alloys were found to exhibit marked differences depending on the intermetallic phases and the heat treatment conditions. SEM-analysis revealed the existence of Al3Ni-phases and the microstructure of broken tensile specimens show both the particle fracture and interface de-bonding affect the fracture behavior of the alloys.

KEYWORDS
Tensile properties, Al3Ni particle, Precipitation hardening, Fracture behavior, SEM

Cite this paper
A. Hossain , A. S. W. Kurny (2014). The Effects of Ni on Tensile Properties of Al-6Si-0.5Mg Cast Alloys during Precipitation Hardening. Chemical and Materials Engineering, 2 , 9 - 13. doi: 10.13189/cme.2014.020102.