Three Dimensional Printing of Multiscale Carbon Fiber-Reinforced Polymer Composites Containing Graphene or Carbon Nanotubes

Abstract

Three-dimensional printing offers a promising, challenging opportunity to manufacture component parts with ad hoc designed composite materials. In this study, the novelty of the research is the production of multiscale composites by means of a solvent-free process based on melt compounding of acrylonitrile–butadiene–styrene (ABS), with various amounts of microfillers, i.e., milled (M) carbon fibers (CFs) and nanofillers, i.e., carbon nanotubes (CNTs) or graphene nanoplatelets (GNPs). The compounded materials were processed into compression molded sheets and into extruded filaments. The latter were then used to print fused filament fabrication (FFF) specimens. The multiscale addition of the microfillers inside the ABS matrix caused a notable increase in rigidity and a slight increase in strength. However, it also brought about a significant reduction of the strain at break. Importantly, GNPs addition had a good impact on the rigidity of the materials, whereas CNTs favored/improved the composites’ electrical conductivity. In particular, the addition of this nanofiller was very effective in improving the electrical conductivity compared to pure ABS and micro composites, even with the lowest CNT content. However, the filament extrusion and FFF process led to the creation of voids within the structure, causing a significant loss of mechanical properties and a slight improvement of the electrical conductivity of the printed multiscale composites. Selective parameters have been presented for the comparison and selection of compositions of multiscale nanocomposites.

Polymeric composites in extrusion‐based additive manufacturing: a systematic review

“…Also with application‐focused purposes, Thomas 104 added carbon fibers and graphene to a PET matrix, obtaining an electrically conductive composite with high tensile strength and ductile fracture behavior, and successfully producing a cubic microsatellite structure. In another investigation of reinforcements with different length scales, Residori et al 135 produced ABS‐based multiscale composites with carbon fibers and nanofillers, that is, carbon nanotubes (CNTs) or graphene nanoplatelets (GNPs). Conductive compositions were likewise achieved by Xiang et al 129 through the compounding of TPU with carbon nanotubes and graphite nanosheets for manufacturing 3D‐printed flexible piezoresistive sensors.…”

“…The thermal characterization comprises other expressively investigated aspects, such as (I) the mass change with temperature increase, measured from the thermogravimetric analysis (TGA) (n = 26), (II) the heat flow variation in the sample throughout cooling and heating cycles, assessed through differential scanning calorimetry (DSC) (n = 23), and (III) the deformation under sinusoidal stress and temperature variation, evaluated from the dynamic mechanical analysis (DMA) (n = 11). In addition, more specific thermal properties were also punctually quantified, such as the heat deflection temperature, 135 the Vicat softening temperature, 135 the Joule effect, 117 diffusivity, 110 and conductivity. 83,97,114,146,172 Figure 8 presents the number of occurrences associated with the three most widely investigated behaviors regarding the characterization of composite materials for 3D printing.…”

Alignment Control of Ferrite-Decorated Nanocarbon Material for 3D Printing

“…Building on the concept of anisotropy, “multiscale 3D printing” [ 2 , 3 , 4 , 5 ] is a method aimed at achieving optimal performance through the design and manipulation of internal structures. This approach extends the overall performance beyond the inherent properties of the base materials.…”