Abstract:
In the present work, the effects of pressure on the wear resistance characteristics, mechanical properties and the microstructures of Al–Si piston alloys that have variable Magnesium (Mg) content are studied. The paper begins with an explanation of the desirable properties of
eutectic Al–Si alloys and why these chemical and mechanical properties are desirable in the fabrication of light weight machine components. The methods for further
strengthening the alloys using alloying elements such as Ni, Cu and Mg, and applying heat treatment are also discussed.
The paper also emphasises on the addition of
Magnesium, and compares the traditional gravity die casting with a novel hybrid technology known as squeeze casting. In the results and discussion section, the
microstructure properties of the Al–Si both as-cast and after heat treatment conditions are discussed. The mechanical and wear properties as well as the implications
of pressure on the alloys are also discussed in details. SEM analyses of wear surface and fracture behavior on the as cast Al–Si alloys and after heat treatment, reveal that
squeeze pressure increases fracture ductility as well as resistance to wear; more so upon heat treatment. It is also
determined that the hardness and UTS values increases with increase in Magnesium content and reaches the maximum values when Mg content is at 1 % of the alloy’s
composition.
