A Transatlantic Institute for Volumetric Powder Bed Fusion

尽管增材制造（AM）行业预计将以越来越快的速度增长，但阻碍额外增长的最重要障碍之一是大多数增材制造技术的缓慢构建速度。跨大西洋体积粉末床熔合研究所（PBF）致力于消除这一障碍。PBF是一种增材制造技术，通过选择性地将粉末材料与热源（通常是激光）逐层融合来制造零件。它是用于构建功能性最终用途部件的最广泛使用的增材制造技术之一，但它可能相当缓慢，需要数小时或数天才能构建大型部件。该项目的目标是为体积PBF工艺建立研究基础，该工艺有可能通过体积烧结而不是逐层烧结来提高生产率超过一个数量级。该项目是德克萨斯大学奥斯汀分校和诺丁汉大学的领先AM研究人员之间的合作，英国ESPRC承诺提供相应的资金，因此预计将为美英合作建立一个新的框架，以克服当前AM技术的局限性。国际学生和教师交流、虚拟学院和本科生研究项目的机会将加强合作，并为国际交流和指导提供机会。该奖项由国际科学与工程办公室共同资助。这项研究超越了目前基于层的方法，以体积的方式快速创建3D对象。体积PBF的研究路径是将粉末材料与有图案的掺杂物分层沉积。该掺杂剂将被设计成选择性地吸收微波/射频能量。一旦层形成，体积将受到微波/射频场的影响，仅在掺杂物存在的地方烧结，从而消除了逐层加热的需要，并提高了构建速度。为了实现这种体积PBF能力，基础研究任务计划建立我们的知识，掺杂剂如何影响射频/微波辐射诱导的聚合物粉末床的选择性加热。计算和物理实验将确定适当的掺杂剂和浓度以及加工条件，以最大限度地提高零件精度和机械性能，并最大限度地减少加工时间。物理实验还将确定最佳的材料喷射路线，以便在选择区域上准确均匀地沉积掺杂剂，并快速蒸发溶剂载体。

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.