Effect of Fiber Content on the Preparation and Mechanical Properties of 3D Printed Short Carbon Fiber Reinforced PA Composites

3D-printed short-carbon-fiber-reinforced thermoplastic composites have attracted significant attention from both the academic and industrial communities due to their remarkable advantages such as lightweight, high strength, and recyclability. However, in most of the current 3D-printing-related nylon composites, the content of short carbon fibers is generally low, and the influence laws of short carbon fibers on the mechanical properties of the composites have not been fully explored. This paper focuses on short-carbon-fiber-reinforced nylon (SCF/PA) composites with short-carbon-fiber contents of 15 wt%, 25 wt%, and 35 wt%, respectively. It studies in depth their mechanical properties and related characteristics. The research results show that with the increase in the short-carbon-fiber content, the melt flow rate of the SCF/PA composites shows a downward trend. In terms of mechanical properties, when the short-carbon-fiber content is 25 wt%, the tensile strength and flexural strength of the composite reach their maximum values, which are 101.43 MPa and 173.16 MPa, respectively. Compared with pure nylon, the improvement ranges are 17.01% and 21.4%, respectively. When the short-carbon-fiber content is 35 wt%, the impact resistance of the material reaches its optimal value, which is 6.02 KJ/m², an increase of 38.1% compared with pure nylon. At the same time, when the short-carbon-fiber content is 35 wt%, the thermal deformation temperature of the material also shows a certain degree of slight increase. In summary, the research results of this paper will provide more abundant and detailed experimental data support for 3D-printed short-carbon-fiber-reinforced nylon composites in various different application scenarios, facilitating further exploration and application in related fields.