Development of Characterization of 3D-Printed Continuous Pitch Carbon Fiber Composites

This study looks at the development of 3D printing technologies for the purpose of creating thermally conductive composites using continuous pitch carbon fiber and how various printing parameters affect thermal conductivity of samples. An initial prototype 3D printer was made with a custom dual nozzle extruder to print pitch carbon fibers, initial samples were measured with 37.1 W/mK effective thermal conductivity, this was much lower than what was expected of the samples. Imaging and µCT scanning confirmed fibers were breaking at some point in the process. A heat flow meter in a vacuum chamber was designed and fabricated to measure thermal conductivity of individual tows of carbon fibers to characterize breakage. The printing parameters affecting breakage were diagnosed and it as found that the angle between the nozzle and the printing bed had the greatest impact on breakage after a new printing system was developed using a 6-axis robot arm.