Aluminium‐carbon nanotubes composites produced from friction stir processing and selective laser melting

Abstract

Aluminium reinforced with multi-wall carbon nanotubes was produced using friction stir processing and selective laser melting. Very fine grains were successfully achieved in both methods with high Vickers hardness values. Cavities were present in selective laser melting of AlSi10Mg reinforced with multi-wall carbon nanotubes parts resulting in higher stress concentration brittle fracture appearance. The high laser absorption and higher thermal conductivity of multi-wall carbon nanotubes resulted in the formation of the cavities in the melted parts. However, the fractography images showed dimpled like appearance indicating a ductile fracture mechanism. Multi-wall carbon nanotubes were observed at the fracture sites indicating the presence of a crack-bridging mechanism. In comparison to carbon nanotubes reinforced aluminium by friction stir processing, selective laser melting produces aluminium reinforced aluminium with better mechanical properties.

Microstructural and Mechanical Characterization of Aluminum Matrix Composites Produced by Laser Powder Bed Fusion

“…The same reaction was detected also by Chang et al, who reported the formation of non‐elongated Al 4 SiC 4 grains . Du et al compared the mechanical properties of AlSi10Mg and AlSi10Mg‐MWCNTs produced via LPBF with the corresponding materials obtained by casting . It was pointed out that, even if the LPBF process produces a huge increase in the mechanical properties of the aluminum alloy, the introduction of the second phase in the LPBF samples reduces the AlSi10Mg mechanical properties.…”

Different reinforcement strategies of hybrid surface composite AA6061/(B4C+MoS2) produced by friction stir processing

“…Recently, friction stir processing has exposed the great potential for fabricating surface composites owing to its solid-state nature [8][9][10][11][12]. Friction stir processing is a unique variant of friction stir welding process, which has the same process principle of the friction stir welding [13,14].…”

Advancements in Laser Powder Bed Fusion of Carbon Nanotubes-Reinforced AlSi10Mg Alloy: A Comprehensive Analysis of Microstructure Evolution, Properties, and Future Prospects

“…The incorporation of CNTs into the AlSi10Mg matrix can induce a transition in the solidification regime, shifting from a dendritic microstructure to a cellular-dendritic microstructure [162,163];…”

“…Vaporization and decomposition of CNTs due to the interaction with the laser, leading to the generation of gases [82,158,162].…”

“…It is important to note that the term "gas" referred to in the aforementioned factors encompasses hydrogen, argon, helium, nitrogen, methane, and traces of carbon monoxide. These gases can originate from various sources, such as the presence of moisture in the L-PBF chamber or the vaporization of CNTs during the printing process [158,162,166].…”