Although the additive manufacturing (AM) industry is projected to grow at an increasing rate, one of the most significant barriers to additional growth is the slow build speed of most AM technologies. The transatlantic institute for volumetric powder bed fusion (PBF) is focused on removing that barrier. PBF is an AM technology that fabricates parts by selectively fusing powdered material with a heat source (typically, a laser) in a layer-by-layer process. It is one of the most widely used AM technologies for building functional end-use parts, but it can be quite slow, requiring hours or days to build a large part. The objective of this project is to build the research foundation for a volumetric PBF process that has the potential to increase production rates by more than an order-of-magnitude by sintering the parts volumetrically rather than layer-by-layer. This project is a collaboration between leading AM researchers at The University of Texas at Austin and the University of Nottingham, with matching funds pledged from the UK ESPRC, so it is expected to build a new framework for US-UK collaboration to overcome the limitations of current AM technologies. Opportunities for international student and faculty exchanges, virtual institutes, and undergraduate research projects will enhance the collaboration and provide opportunities for international networking and mentoring. This award is co-funded by the Office of International Science and Engineering.
The research moves beyond the current layer-based approach to rapidly create 3D objects in a volumetric fashion. The research path for volumetric PBF is to deposit powdered material with a patterned dopant in a layer-wise fashion. The dopant will be engineered to selectively absorb microwave/RF energy. Once the layers are formed, the volume will be subjected to microwave/RF fields that sinter only where the dopant is present, eliminating the need for layer-by-layer heating and increasing build speeds. To realize this volumetric PBF capability, fundamental research tasks are planned to build our knowledge of how dopants affect selective heating of polymer powder beds induced by RF/microwave radiation. Computational and physical experiments will determine appropriate dopants and concentrations and processing conditions for maximizing part accuracy and mechanical properties and minimizing processing time. Physical experiments will also determine the best material jetting routes to deposit the dopants accurately and uniformly over the selective area and evaporate the solvent carriers quickly.
