Recent work in dispersion-strengthened tungsten alloys as plasma-facing component materials in future fusion reactors

Tungsten is the current material of choice for plasma-facing component envisioned in future nuclear fusion reactor systems. The divertor region of future nuclear fusion reactors will be exposed to extremely plasma fluence of 10²⁶ m^-2 and temperatures in excess of 2000°C. These conditions require materials, such as tungsten and its alloys and composites, with exceptional thermo-mechanical properties. A high melting point, low coefficient of thermal expansion, high sputtering resistance, and high conductivity make tungsten an ideal candidate. In addition, PMI properties such as He exhaust management and hydrogen retention must be addressed.  Despite its desirable traits, sustained plasma exposure can lead to significant microstructural damage in tungsten. In addition, tungsten alloys are susceptible to a high ductile-to-brittle transition temperature and recrystallization under irradiation. To overcome these limitations, the Radiation Surface Science and Engineering Lab (RSSEL) has been developing dispersion-strengthened tungsten (DS-W) alloys. In DS-W, the tungsten matrix is strengthened by carbide particles such as TiC, ZrC and TaC. Our studies showed that DS-W alloys possess improved structure stability and increased radiation resistance compared to the pure tungsten counterpart. Continuing investigations into plasma-material interactions (PMIs) of DS-W and the resulting surface, microstructural and mechanical changes will be presented.