Improvement of impact properties of tungsten by potassium doping

Highlights: • Effects of K-doping on the Charpy impact properties of hot-rolled W plate were investigated. • K-doped W showed increase in USE and decrease in DBTT compared to pure W with the same deformation ratio. • DBTT and USE of W materials from different production routes could be predicted using Hall-Petch type relations regardless of the K-doping. • K-doping simultaneously induced grain refining, suppression of recrystallization, increases in strength, ductility, and impact properties. -- Abstract: Low temperature brittleness and high ductile-to-brittle transition temperature (DBTT) are potential drawbacks related to the mechanical properties of tungsten (W) for divertor application in fusion reactors. To improve the mechanical properties of W, potassium (K) doping has been applied as a dispersion-strengthening method. In this paper, the effects of K-doping on the Charpy impact properties of W plate fabricated by powder metallurgy and hot rolling in the as-received condition were investigated. In addition, the correlation among the impact properties, tensile properties, and grain structure and the advantages of K-doped W for divertor application of fusion reactor were discussed.