Development and characterization of composite materials with multi-walled carbon nanotubes and graphene nanoplatelets for powder bed fusion

Abstract

Purpose With the technological progress, high-performance materials are emerging in the market of additive manufacturing to comply with the advanced requirements demanded for technical applications. In selective laser sintering (SLS), innovative powder materials integrating conductive reinforcements are attracting much interest within academic and industrial communities as promising alternatives to common engineering thermoplastics. However, the practical implementation of functional materials is limited by the extensive list of conditions required for a successful laser-sintering process, related to the morphology, powder size and shape, heat resistance, melt viscosity and others. The purpose of this study is to explore composite materials of polyamide 12 (PA12) incorporating multi-walled carbon nanotubes (MWCNT) and graphene nanoplatelets (GNP), aiming to understand their suitability for advanced SLS applications. Design/methodology/approach PA12-MWCNT and PA12-GNP materials were blended through a pre-optimized process of mechanical mixing with various percentages of reinforcement between 0.50 wt.% and 3.00 wt.% and processed by SLS with appropriate volume energy density. Several test specimens were produced and characterized with regard to processability, thermal, mechanical, electrical and morphological properties. Finally, a comparative analysis of the performance of both carbon-based materials was performed. Findings The results of this research demonstrated easier processability and higher tensile strength and impact resistance for composites incorporating MWCNT but higher tensile elastic modulus, compressive strength and microstructural homogeneity for GNP-based materials. Despite the decrease in mechanical properties, valuable results of electrical conductivity were obtained with both carbon solutions until 10–6 S/cm. Originality/value The carbon-based composites developed in this research allow for the expansion of the applicability of laser-sintered parts to advanced fields, including electronics-related industries that require functional materials capable of protecting sensitive devices against electrostatic discharge.

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“…Additive manufacturing (AM), also known as 3D printing, is an advanced processing technique to manufacture parts with intricate geometry layer-by-layer using the computer-aided design (CAD) model (Mishra et al , 2022; Negi and Suresh Dhiman, 2016), and a tendency to fabricate personalized and customized products with minimal material waste. Various AM processes such as fused deposition modeling (FDM) (Ahmad et al , 2023; Kumar and Negi, 2023a, 2023b), selective laser sintering (SLS) (Lopes et al , 2023; Parandoush and Lin, 2017), stereolithography (SLA) (Borra and Neigapula, 2023; Negi et al , 2023), direct ink writing (DIW) (Mantelli et al , 2021), inkjet printing (IP) (Nachimuthu and P.K., 2023), poly-jet printing (PJP) (Liu et al , 2022), etc. are playing a significant role in Industry 4.0.…”