NSF-EPSRC A Transatlantic Institute for Volumetric Powder Bed Fusion

加法制造(AM)不仅给现代制造业带来革命性的变化，而且还给整个产品开发周期带来革命性的变化，包括设计的产品类型和交付产品的供应链。通过只将材料放置在需要的地方，以附加的、分层的方式，可以创建非常复杂的架构和功能分级功能，以增强产品的功能。通过直接从数字文件制造零件，不需要所需的工具或夹具，在本地小批量制造零件是经济的，从而为个人定制和独一无二的制造和维修打开了大门。尽管AM使小批量生产复杂零件成为可能，但相对于高通量的传统制造方法，添加制造零件的速度慢且成本高是AM发展的主要障碍这些障碍对于粉末床熔化过程来说尤其严重。例如，激光烧结(LS)是应用最广泛的终端部件AM技术之一，可能需要超过24小时才能制造出一整批聚合物部件。零件是一层一层地建造的，通常厚度约为100微米，方法是用激光烧结粉末，激光以类似于栅格的图案跟踪零件的连续横截面。根据横截面的复杂程度，每一层可能需要60秒或更长时间来准备和制造，从而导致构建时间过长。结合建造后冷却操作，完整建造的周期时间可接近36小时。尽管最近的技术进步提高了处理速度，但这些改进基本上仍然是以逐层方式制造物体，因此在加固材料的速度方面固有地受到限制。我们建议对烧结件进行体积加固，与商用LS相比，周期时间至少缩短了25倍，同时能够烧结更多种类的聚合物材料。

Additive manufacturing (AM) is revolutionizing not only modern manufacturing but also the entire product development cycle, including the types of products that are designed and the supply chains through which they are delivered. By placing material only where it is needed, in an additive, layer-wise fashion, it is possible to create very complex architectures and functionally graded features that enhance the functionality of a product. By fabricating a part directly from a digital file, with no required tooling or fixtures, it is economical to fabricate parts locally in small quantities, opening the door to personal customization and one-of-a-kind fabrication and repair. Although AM enables production of complex parts in small volumes, the slow speed and high cost of additively manufacturing a part-relative to high-throughput conventional manufacturing methods-are significant barriers to the growth of AM. The barriers are particularly acute for powder bed fusion processes. For example, laser sintering (LS), one of the most broadly utilized AM technologies for end-use parts, can require more than 24 hours to fabricate a full batch of polymer parts. Parts are built in layers-typically on the order of 100 microns thick-by sintering powders with a laser that traces successive cross-sections of the part in a raster-like pattern. Depending on the complexity of the cross-section, each layer can require 60 seconds or more to prepare and fabricate, resulting in excessive build times. Combined with post-build cooling operations, the cycle time for a full build can approach 36 hours. Although recent technological advances have improved processing speeds these improvements are still essentially fabricating objects in a layer-by-layer manner and are therefore inherently limited in terms of the speed with which they consolidate material. We propose to consolidate sintered parts volumetrically, resulting in at least a 25 time reduction in cycle time relative to commercial LS, along with the ability to sinter a wider variety of polymer materials.