Blending of Fiber Reinforced Materials Using Big Area Additive Manufacturing (BAAM)
Functionally graded materials (FGM) are attractive for their use in additive manufacturing (AM) systems because they allow for the use of a less expensive material with sub-optimal mechanical properties for the majority of the part, while using a more expensive, higher performance material in selected areas where needed. This approach has the potential to optimize cost with weight and mechanical performance. FGMs have been studied extensively in the area of hybrid composites, but the application of FGM is not common in additive manufacturing due to the widespread use of homogeneous feedstock materials. The Big Area Additive Manufacturing (BAAM) system has the potential to print FGM structures because it uses a pelletized feedstock that is similar to injection molding and conventional extrusion processes. This approach allows BAAM to blend commodity materials and high performance engineering polymers as needed in a particular part. This study investigates the transition between BAAM materials as a function of extrusion screw design and processing conditions. Specifically, the transition between acrylonitrile butadiene styrene (ABS) and carbon fiber reinforced ABS is analyzed, and a fiber content shape function is generated to characterize the degree of blending.
Author: Zeke Sudbury
Conference: SAMPE Seattle 2017