Work

Carbon-nanotube-length dependent interfacial reaction in aluminum matrix composites and its effect on strengthening

Year: 2025

Type: article

Abstract: The interfacial reaction is a critical factor affecting the strengthening effect of carbon nanotubes (CNTs) in metal matrix composites . In this work, the effects of CNT length on the morphology and formation mechanism of interfacial aluminum carbide (Al 4 C 3 ) in aluminum (Al) matrix composites were investigated. By observing a vast number of Al 4 C 3 in Al composites which were reinforced with CNTs by different aspect ratios, three kinds of morphologies (skinny, twinned and chunky) were identified. Analyses on intermediate reaction products of these three kinds of Al 4 C 3 revealed that their length increased with the increase of CNT length, but their morphologies had a weak relationship with CNT length. The morphologies were determined by the dispersion state of CNTs, the nucleation sites of Al 4 C 3 and element diffusion modes. Both the two debating mechanisms for Al 4 C 3 formation, viz., carbon-atom-diffusion mechanism and carbon-template-growth mechanism, were confirmed for the rod-shaped skinny and twinned Al 4 C 3 , respectively. Chunky Al 4 C 3 shared a similar formation mechanism with twinned Al 4 C 3 while it formed at CNT cluster. The growing process and strengthening effects of the three kinds of interfacial Al 4 C 3 with different lengths were thoroughly discussed. This study may provide guidance to control the interface in nano-carbon-reinforced Al matrix composites for superior properties.

Source: Carbon

DOI: 10.1016/j.carbon.2025.120353