International Journal of Science, Engineering and TechnologyAuthors: Rutuja Sunil Jadhav, Professor Dr. Pankaj P. Awate
Abstract: Aluminum matrix nanocomposites have attracted considerable attention in recent years due to their superior mechanical properties, lightweight nature, and potential for advanced engineering applications. Among various aluminum alloys, A357 is widely used in the automotive, aerospace, and marine industries because of its excellent castability, good corrosion resistance, and favorable strength-to-weight ratio. However, the mechanical performance of unreinforced A357 alloy can be further enhanced through the incorporation of nanoscale reinforcements such as multi-walled carbon nanotubes (MWCNTs). In the present investigation, A357 aluminum alloy reinforced with different weight fractions of MWCNTs was successfully fabricated using the stir casting technique. Stir casting was selected owing to its simplicity, low production cost, and suitability for large-scale manufacturing. The fabricated nanocomposites were evaluated to determine the influence of MWCNT reinforcement on their mechanical properties, including ultimate tensile strength, yield strength, hardness, and ductility. In addition, microstructural characterization was carried out using optical microscopy and scanning electron microscopy (SEM) to examine the dispersion of MWCNTs, grain refinement, and the quality of interfacial bonding between the matrix and reinforcement. The experimental results revealed that the incorporation of MWCNTs significantly enhanced the mechanical performance of the A357 alloy up to an optimum reinforcement level. Maximum improvement was observed at approximately 1.0 wt.% MWCNT, owing to the uniform distribution of nanotubes, effective load transfer, and grain refinement. Further addition of MWCNTs resulted in a slight reduction in mechanical properties because of nanotube agglomeration and increased porosity. The developed A357–MWCNT nanocomposites exhibit improved strength and hardness while maintaining acceptable ductility, making them promising candidates for lightweight structural components in automotive, aerospace, and other high-performance engineering applications.
