Additive Manufacturing of Carbides and their composites

碳化物以其机械强度、硬度和热稳定性而闻名。工业上对碳化硅(SIC)和碳化硼(B4C)的小而复杂的零件越来越感兴趣，用于航空航天、交通运输和其他应用。然而，传统的成型工艺需要昂贵的模具，而且很难生产出这些复杂的几何形状。添加制造(AM)提供了一种很有前途的替代方法，然而，由于碳化物的高熔点和光学性质，它与碳化物作斗争。该项目的总体目标是生产碳化硅、碳化硼及其复合材料的细小、致密、复杂的部件。首先，正在研究的三种技术是机器人辅助沉积(或机器人铸造)、二极管区域熔化(DAM)和数字光处理(DLP)。机器人铸造是一种使用假塑性墨水的连续挤压技术。这项技术将被用于研究反应结合的碳化硅以及碳化硅与碳化硅纤维的结合。另一方面，DAM通过激光吸收使粉床致密，人们正在探索将还原的氧化石墨烯作为一种潜在的添加剂来增加陶瓷粉末的吸收。最后，DLP是基于掩模的立体光刻的衍生产品。将开发光敏悬浮液，并将测试打印部件的机械性能，以尝试开发成功的打印工艺。

TheCarbides are renowned for their mechanical strength, hardness and thermal stability. There is increasing industrial interest for small, complex parts of silicon carbide (SiC) and boron carbide (B4C) for aerospace, transportation and other applications. However, traditional forming processes require expensive moulds and struggle to produce these complex geometries. Additive manufacturing (AM) offers a promising alternative however, it struggles with carbides due to their high melting points and their optical properties. The overall aim of the project is to produce small, dense, complex parts of silicon carbide, boron carbide and their composites. To begin with the three techniques being investigated are robotic assisted deposition (or robocasting), diode area melting (DAM) and digital light processing (DLP). Robocasting is a continuous extrusion technique using pseudoplastic inks. The technique will be used to investigate reaction bonded SiC as well as SiC matrices with SiC fibres. On the other hand, DAM densifies a powder bed through laser absorption and reduced graphene oxide is being explored as a potential additive to increase the absorption of ceramic powders. Finally, DLP is a mask-based derivative of stereolithography. Photosensitive suspensions will be developed, and the mechanical properties of printed parts will be tested to try to develop a successful printing process.