Carbon Nanotubes (CNTs) are considered as an ideal reinforcement to improve the properties of the Aluminium (Al) matrix composites. Even though a significant improvement in mechanical, thermal and electrical properties obtained in Al-CNT composites, there are still several challenges to get uniform dispersion in the matrix and interfacial bonding between CNTs and Al matrix. The objective of the present work is to study the influence of ball milling time on structural stability and distribution of CNTs in Al matrix. The fabricated composite powders morphology like grain size and CNT structural quality were analyzed using Scanning Electron Microscope (SEM), X-ray diffraction (XRD) and Raman spectroscope. It was found that the 6 hrs of ball milling is an effective way to achieve homogeneous distribution of CNTs in Al matrix. The highest hardness value of 77.4 Hv was obtained at 6 hrs ball milling time and subsequently the hardness was reduced to 46.2 Hv at 12 hrs. The reduced hardness of Al-CNT composites may be attributed to lower structural qualities of CNTs with longer milling time. This is evident from the ID/IG values of 0.92 and 1.04 for the 6 hrs and 12 hrs ball milled composites respectively.

Keywords: Carbon Nanotubes, Aluminium, Ball Milling, Structural stability, Hardness