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The selection of optimal process parameters has a decisive effect on the quality of 3D printing. In this work, the numerical and experimental methods were employed to investigate the FDM printing deposition process of PLA/GNPs nanocomposite. The effect of process parameters on cross-sectional morphology and dimension of the deposited filament, as well as the mechanical property of the FDM printed specimens were studied. The extrusion and the deposition process of the molten PLA/GNPs nanocomposite was simulated as a fluid flow by the paradigm of CFD, the effects of printing temperature and shear rate on thermal-physical properties, such as viscosity and surface tension, were considered in models. Under the assumptions of non-Newtonian fluid and creep laminar flow, the deposition flow was controlled by two key parameters: the nozzle temperature and the nozzle velocity. The numerical model was verified by experiments from four aspects of thickness, width, area, and compactness of the deposited PLA/GNPs nanocomposite filament cross-section. Both the numerical simulation and experiment results show that with the increase of nozzle temperature and nozzle velocity, the thickness, area, and compactness of the deposited filament decreases. While the width of deposited filament increased with the increase of nozzle temperature and decrease of nozzle velocity. The decrease in thickness and the increase in width caused by the change of process parameters reached 10.5% and 24.7%, respectively. The tensile strength of the printed PLA/GNPs specimen was about 61.8 MPa under the higher nozzle temperatures and velocity condition, an improvement of 18.6% compared to specimen with the tensile strength of 52.1 MPa under the lower nozzle temperatures and velocity condition. In addition, the experimental results indicated that under the low nozzle velocity and nozzle temperature condition, dimensional standard deviation of the printed specimens decreased by 52.2%, 62.7%, and 68.3% in X, Y, and Z direction, respectively.

Carbon‐reinforced polymer matrix composites (PMCs) have been thoroughly applied in different fields because of their benefits, such as low specific gravity, corrosion resistance, good electrical conductivity, and robust mechanical properties. Especially, with the emergence of fused deposition modeling (FDM) technology has further promoted the application of such materials in complex structural components. Recently, FDM printing carbon‐reinforced PMCs have become a hot topic in composites research, and many promising results have been achieved around related research. In order to help readers have a comprehensive and systematic understanding of the latest research progress of FDM printing carbon‐reinforced PMCs in terms of material modification, processing, material properties, and application levels, this paper reviews the properties and processes of FDM printed carbon‐reinforced PMCs and their potential applications in aerospace, flexible sensing, electrochemistry, and biomedical fields. The effects of commonly used carbon reinforcing materials on the performance of FDM printed PMCs were contrasted and analyzed. Moreover, the process optimization of printing carbon‐reinforced PMCs was introduced and highlighted. Finally, the current challenges and future research directions of FDM printing carbon‐reinforced PMCs were analyzed and prospected.