Low-Cost Rapid Joining for Fabrication/In-Situ Repair of Large SiC Composite Structural Materials for Fusion Reactors and Other Commercial Applications

72119S03- I In-vessel components for future fusion energy systems must withstand high levels of surface heat flux and neutron wall loads. SiC composite materials, especially SiCf/SiCm composites, have the desired characteristics for this application; however, they would be suitable for only a small portion of the overall structure because of limitations in the sizes and shapes that can be made with reasonable production costs. In order to fully utilize this material, individual units must be joined to form the complete first wall or other structural components for fusion reactors. This project will develop a low-cost, effective joining technology for the fabrication and in situ repair of large SiC composite materials. The technology would be used to join components and subassemblies at the site of fusion plant, rather than producing large and delicate assemblies at different sites and shipping them to the fusion plant. Phase I will address basic engineering and physics issues to determine an optimized joining scheme for composite coupons. A model will be developed and experiments conducted to benchmark the modeling predictions and identify the control parameters needed to produce reliable joints in a cost-effective manner. Plans for neutron-irradiation tests of the joined samples will be developed, and test samples will be designed. Commercial Applications and Other Benefits as described by awardee: The joining technology should decrease the costs of fabrication of SiC/SiC composites for many applications. Specifically, the production of the composites proposed for the next generation fusion reactor would benefit significantly from a technology that can be used for fabrication and repair at the site. Additionally, this technology could be used in the making of other SiC-based components for the hot zones of gas turbines, leading edges of wings and nose structures of advanced aircraft and missiles, high temperature heat exchangers, and radiant burner tubes.