Powder Metallurgical Processing of Aluminium Metal Matrix Composites Reinforced with Graphite

aircraft and automotive industries, it is preferable to use lightweight yet strong
material especially aluminium. Due to high strength to weight ratio, automobile and
aircraft component are generally made out of Aluminium alloy which makes the
transport lighter and indirectly results in saving fuel consumption. However, the used of
Aluminium alloy has been limited because of unfavourable wear. In this project, to
improve the wear resistance, the author has dispersed graphite particles in the
aluminium metal matrix composites. Aluminium-Graphite composite was processed and
was used for the analysis. The main objective of this project is to further reduce the
density of aluminium matrix reinforced with graphite. Other than that, this project also
done to investigate the wear resistance behaviour of the composites with different
amount of graphite. The third objective of this project is to compare the microstructure
and physical properties between aluminium and aluminium reinforce with graphite with
different percentage of graphite amount. All the samples needed in this research were
prepared by the author using powder metallurgy hot pressing process. The wear
behaviour of the composites with different amount of graphite was investigated using
pin on disc method while the hardness of each sample with different weight percentage
of graphite was determined using Vickers microhardness test machine. Then, the author
examines the improvement of sample's microstructure using Scanning Electron
Micrograph (SEM) and X-Ray Diffraction (XRD) method. The result shows that the
density of the composites is decreased after hot pressing process. Hardness of the
unreinforced aluminium matrix is improved from 22.2HV to 66. 7HV after been
reinforced with increasing wt"/o of graphite. From the experiment, adding only 2% of
graphite results in highest wear resistance. As for the micrograph analysis, the increment
of graphite amount in aluminium based composites is proven and no new phases are
formed in the composites. Most of the objectives of this project are achieved except for
wear resistance behaviour where the results obtained are not as expected by the author
but still it is a good finding.