Comparison of Mechanical Properties and Microstructure of Aluminum alloy Micron and Nano SiC Composites fabricated by Ultrasonic Vibration

Abstract

Aluminium and aluminium alloys are widely used in industries due to low density, high corrosion resistance
and thermal conductivity. However, in the engineering application aluminium alloys still have some problems such as
relatively low strength, unstable mechanical properties. The mechanical properties can be improved by addition of
ceramic particles like SiC etc. to fabricate metal matrix composites (MMCs). These composites are not only light weight,
but have high-strength, Stiffness and wear resistance. In this study, AA 5083 alloy Micron and Nano SiC composites have
been fabricated by Ultrasonic assisted Stir casting. Different weight % of Micron SiC (3, 5, 8, 10 Wt %) & Nano SiC (1,
2, 3 and 4 wt %) were used for synthesis of composites. Density, Elastic modulus, Tensile strength, Compressive
Strength, Elongation, Hardness for aluminum alloy micron and nano SiC composites were measured. Microstructure
characterization of both micron and nano SiC composites were carried out. Results revealed that porosity increases with
increase the weight percentage of SiC. Al Nano SiC shows higher value of elastic modulus, tensile strength, compressive
strength than Al Micron SiC Composites. Hardness of composites increases with increase in weight percentage of SiC.
SEM micrograph shows uniform distribution of SiC particles with some places agglomeration. The application of
ultrasonic vibration on the composite during melting not only refined the grain microstructure of the matrix, but also
improved the distribution of Sub micron and nano-sized particles.