SiC-SiC Slurry Bonding

SiC is an excellent material for fusion reactor environments, including first wall plasma facing materials and breeder-blanket modules. It is also being considered as structural elements in Small Modular Advanced High-Temperature Reactor (SmAHTR) because of its low-activation, temperature resistance, and radiation damage tolerance compared to most materials. The challenge is in joining the SiC-SiC composites to create structural elements with joining materials that are irradiation tolerant at high temperatures with good bond strength. A novel process technology, i.e., supersonic high pressure particle deposition of joint material, followed by a consolidation process, will be utilized to achieve excellent bond quality, with the objective of obtaining strong joints that are resistant to thermal cycling at a reduced cost of processing to increase the level of manufacturability. The proposed approach could provide a large area, uniform and conformal strong bond between the joining materials and the SiC/SiC composite. The focus of Phase I is the utilization of Ti and Ti composites as joining materials as these have previously showed good bond strength, and most importantly they exhibited excellent irradiation stability. Characterization of the interfacial microstructure and residual stresses will allow optimization of process parameters to enhance the resistance of such joints to thermal cycling. The processing parameters for the supersonic deposition will be investigated to maximize uniformity and bonding, and to reduce the magnitude of stresses in the composite. Joint samples will be microstructurally and mechanically characterized to demonstrate the feasibility of the proposed concept. Commercial Applications and Other Benefits: The primary market opportunity is the nuclear industry, but this concept of using the supersonic high pressure cold spray for joining can also extend to joining many other dissimilar materials.