Abstract:
Currently, advancements made in the field of metal matrix composites to reduce the
weight and cost of materials, especially aluminum matrix composites are preferable
types of metal matrix composites due to lower weight-to-strength ratio and significant
improvements in their mechanical properties. To improve the aluminum matrix's
mechanical and physical qualities, such as tensile strength, compressive strength,
hardness strength, impact strength, wear, and density to a certain limit. Silica is one of
the reinforcements with a low density that is widely available. In this study, the most
widely available aluminum alloy 6063 was used as a matrix and 150 µm particle size
of Ethiopian silica sand powder with 92.8 % of purity as reinforcement by using the stir
casting method for three-wheeler Bajaj connecting rod application. By this method, five
samples with 0 %, 5 %, 10 %, 15 %, and 20 % of locally available silica sand
reinforcement were prepared. The stirring was done by using a hand drill machine that
has a stirring speed of 600 rpm for 5 minutes. After the composite samples were
successfully produced for each sample, the compression test, tensile test, impact test,
hardness test, wear test, density measurement, and microstructure study were conducted
to investigate the impact of the reinforcement's weight percentage on the matrix. When
Ethiopian silica sand reinforcement was added to the matrix, the density was reduced,
but compressive strength, hardness strength, and wear resistance, were all increased.
Whereas the tensile strength and impact strength increased up to 15 % of reinforcement
weight percentage only. The microstructural analysis showed that the matrix's
reinforcements were evenly dispersed at S1, S2, S3, and S4 with minor clustering of
sand observed at S3 and S5. From this study, the fabricated composite material with 84
% of AA6063, 15 % of silica sand, and 1 % of magnesium powder provided a better
combination of properties and can be considered as an alternative material for the
existing three-wheeler Bajaj connecting rod which requires high strength, lower
density, and better grain boundaries.
Keywords: AA6063; Metal matrix composite; Silica sand concentration; Properties;
Microstructures.