Morphology Studies on Mechanically Milled Aluminium Reinforced with B4C and CNTs

Abstract

Carbon nanotubes (CNT) with exceptional mechanical and physical properties are the prime candidate materials for metal matrix composites. But the dispersion of CNTs in the metal matrix is affected by attractive van der Waals forces. In this study, we have adopted ultrasonication and mechanical alloying to achieve homogenous dispersion of multiple reinforcements namely B4C and CNTs within the commercial purity aluminium powder. The ultrsonication of all the starting materials was followed mechanical alloying process which was carried out in a planetary ball mill up to 480 min. The milling process was systematically studied by taking a small amount of milled powder at different milling time of 60, 120, 240 and 480 min respectively. The effect of ultrasonication and mechanical alloying on both morphology of the powders and dispersion of B4C and CNTs was studied using scanning electron microscopy. The results showed uniform dispersion of both B4C and CNTs within the pure aluminium powders without any agglomeration. Both the pure aluminium and hybrid nanocomposite powder showed decrease in particle size from 20.89 µm to 5.67 µm and 2.72 µm respectively after 480 minutes of ball milling.