Effect of Initial Aluminum Alloy Particle Size on the Damage of Carbon Nanotubes during Ball Milling

Abstract

Damage to carbon nanotubes (CNTs) during the fabrication process of CNT reinforced composites has great influence on their mechanical properties. In this study, the 2014 Al with powder sizes of 20, 9 and 5 μm was selected to study the effect of initial particle size on the damage to carbon nanotubes (CNTs) during ball milling. The result shows that for CNTs in the ball milled CNT/Al (with powder size of 20 and 9 μm) mixtures, the intensity ratio of the D band and the G band (ID/IG) first increased and then reached a plateau, mainly because most of the CNTs are embedded, to a certain extent, in the aluminum powder after milling, which could protect the CNTs from damage during further milling. While for CNTs in the ball milled CNT/Al (with powder size of 5 μm) mixture, the ID/IG ratio continues to climb from 1.31 to 2.33 with time, indicating continuous damage to the CNTs occurs during the milling. Differential scanning calorimetry (DSC) analysis demonstrates that the chemical instability increased with an increase in the damage level of CNTs, resulting in the formation of aluminum carbide (Al4C3) at a lower temperature before the melting of aluminum, which is detrimental to their mechanical properties.

Titanium Carbide Nanofibers-Reinforced Aluminum Compacts, a New Strategy to Enhance Mechanical Properties

“…In conventional MMCs, the most widely used reinforcements are ceramics, such as Al 2 O 3 or SiC, in the form of fibers, flakes or particulates [ 6 , 7 , 8 , 9 ]. While regarding fibers at the nanoscale one of the most recently studied reinforcement for Al alloys are Carbon Nanotubes CNT [ 10 , 11 , 12 ]. Thus, aluminum based metal matrix composites reinforced by particles and fibers are successfully applied in various fields of automotive and aircraft industry.…”

Development and Investigation of The Production Process of the Aluminum Matrix Composition Mechanically Alloyed With Single-Walled Carbon Nanotubes and the Composition Material Made of it

“…During the normalization process within 160 min the mixture bulk density was decreasing till the stationary value 0,34…0,36 g/cm 3 (Fig. 1) suggesting the right choice of the low-energy impact level with excluding the cold-welding process being characterized with CP forming and increasing of their bulk weight.…”

“…Several researchers [1][2][3][4][5] testified that the achievement of high physical and mechanical properties by aluminum matrix compositions is based on the effective dispersion of carbon nanotubes (CNT) in the aluminum matrix of the composition material provided at the stage of receiving of the aluminum matrix composition (AMC) including but not limited to the method of mechanical alloying (MA). Authors of these papers fairly argue that clustering and agglomerating of CNT are critical technological issues.…”

Archives of Foundry Engineering

“…Furthermore, it can enhance the dispersibility of the CNTs and promote their interfacial reaction [42][43][44][45]. However, a longer ball milling time does not necessarily lead to a better composite; a too long ball milling time will cause damage to the CNTs [46], and interface reactions are prone to consume the added CNTs at the damage site, resulting in carbides that reduce the quality of interface bonding [47]. In the actual process, smelting aids, process control agents, and nSiC particles can be added as dispersants during ball milling, which can not only avoid damage to the CNTs but also eliminate the oxide film of the aluminum particles, reduce the occurrence of cold welding [48][49][50][51], reduce the shear hysteresis effect of the ball milling process, and promote interface bonding.…”