Effect of Magnesium on the Hardness of Cast Aluminium Alloy Using Sand Casting Method

Abstract

This research paper deals with the casting procedures and testing
process of two metals combined to increase the hardness properties of
the base metal. These two metals comprise of Aluminum (Al) and
Magnesium (Mg) with Aluminum being the base metal. Aluminum
Alloys are preferred in various structural and construction works, also
in the manufacturing of various industrial machine components and
automobile parts due to their favorable properties like low density
which results in their light weight, high strength and superior
malleability compared to iron-carbon alloy like steel and cast iron. In
this study 6 samples of different percentage (%) weight composition of
magnesium alloyed with aluminum was prepared and studied, the
casting process was done using sand casting method because of low
cast and availability. The various compositions by weight of
magnesium are added into the molten aluminum and stirred using stir
casting machine. After solidification for a period of time the samples
were cut and machined to specification to enable the hardness test to
be carried out and this test was done using a Brinell hardness testing
machine at Engineering Management and Development Institute
(EMDI)and the various results inferred from the test were recorded
and analyzed. It was observed from the results that at 4% Mg
composition, the hardness value was lowest and increased gradually,
and at 14% Mg composition the hardness value was highest. It is
therefore concluded that the composition of magnesium greatly
influences the hardness of the Al-Mg alloy cast part. As the %
composition of Mg increases in the alloy, the hardness of the cast
parts also increases.