Scaling Spark Plasma Sintered (SPS) Ultrafine Grain Tungsten for Advanced Nuclear Fusion Reactor Plasma-Facing Components

Nuclear fusion is the holy grail of clean, limitless energy for mankind. Despite decades of work with significant advances, this technology has not yet been realized, due in part to the lack of successful development and scaling of novel advanced fusion materials able to survive within the extreme environment created by the fusion reaction. Although tungsten is a highly promising material, components produced via current manufacturing technologies suffer from embrittlement, recrystallization, and erosion from exposure to high heat and particle flux. The approach of this work is to tune and develop the specific material feed mix and processing conditions of fine grain dispersion-strengthened tungsten with transition metal carbides via spark plasma sintering. Initial results have found that small additions of less than 10% of materials such as zirconium carbide can significantly affect the average grain size and resultant mechanical properties of material fabricated in this method. The total effects of critical manufacturing conditions, including temperature and pressure, on these mixtures however are not fully understood and are critical to mass production. This work will define the implications of these factors on the microstructural and mechanical properties under varying thermal load to develop a pathway for scale up to reactor-level wall components. Phase II will evaluate additional critical properties, including radiation tolerance and liquid metal wettability. The proposed work aims to deliver a critical enabling technology for the development of fusion power reactors: the scaled manufacture of high temperature radiation resistant material for plasma facing components. We anticipate the development of ductile, fine-grain tungsten via scaled spark plasma sintering will significantly advance high-heat flux components. Beyond nuclear fusion, the successful scaling of spark plasma sintering has many applications. Both the particular material of focus and the technique in general have received significant attention for applications in aerospace, defense, manufacturing, and more, but few have bridged the gap to commercialization due to struggles with scalability.