Thermal, Structural, and Mechanical Properties of Carbon Fiber Reinforced <scp>PLA</scp> Composites: Influence of <scp>FDM</scp> Print Speed and Comprehensive Analysis

ABSTRACT Fused deposition modeling (FDM) of carbon fiber reinforced thermoplastics is a key technology for advanced industrial applications due to its simplicity and cost‐effectiveness. The properties of FDM‐printed parts are significantly influenced by printing parameters, necessitating a thorough understanding of their effects. This study investigates the impact of print speed on the thermal, structural, chemical, and mechanical properties of carbon fiber reinforced polylactic acid (CFRPLA), a lightweight composite widely used in engineering. Thermal behavior was analyzed using differential scanning calorimetry and thermogravimetric analysis. Structural and chemical properties were characterized via x‐ray diffraction and Fourier transform infrared spectroscopy. Tensile testing was employed to evaluate mechanical performance. Results reveal that higher print speed promotes CFRPLA crystallinity but reduces thermal stability and degradation resistance. Increased print speed also led to a decrease in stiffness and strength (by 29.7% and 5.1%, respectively), coupled with enhanced ductility and toughness (by 18.77% and 15.4%, respectively), attributed to the presence of large air voids and fiber‐matrix debonding, as observed through scanning electron microscopy (SEM). A competition between crystallinity and porosity in influencing mechanical performance was identified. These findings underscore the importance of optimizing print speed to achieve effective layer bonding and a synergistic interaction between carbon fibers and the PLA matrix, ensuring high‐quality printed components.