2026 Volume 21 Article ID: 1405047
Tungsten (W) is a key plasma facing material (PFM) for future fusion devices, requiring improved ductile-to-brittle transition temperature (DBTT) and recrystallization resistance for long-term operation. Various modification methods of W—including second-phase dispersion (potassium doping (K-doping) and lanthanum oxide (La2O3) particle dispersion) and solid-solution alloying (alloying with rhenium (Re) and tantalum (Ta))—were evaluated in the present study for expanding the operation temperature range of PFMs from DBTT to recrystallization temperature. Both second-phase dispersion and solid-solution alloying were found to expand the operation temperature range, offering greater flexibility in designing plasma facing components. Among the materials evaluated, K-doped W-1%Ta and W-1%Ta appeared particularly promising. Nevertheless, alloying with Ta may have concerns, including higher post-irradiation surface dose rate and poorer machinability. Thermal properties must also be considered for PFM, however solid-solution alloying reduces thermal diffusivity and conductivity, and large dispersed particles such as La2O3 can introduce anisotropy and may reduce thermal diffusivity and conductivity. Therefore, selecting suitable W-based materials requires carefully balancing mechanical property improvements with thermal property limitations to ensure dependable operation in future fusion devices.
