Tungsten–potassium: a promising plasma-facing material

Abstract

Tungsten-potassium (potassium-doped tungsten or WK), initially known from the electric filament industry, is a promising plasma-facing material (PFM) in future fusion facilities like International Thermonuclear Experimental Reactor (ITER). However, the brittle nature of W and irradiation-induced defects of WK materials may result in a risk of deuterium-tritium reaction failure in fusion reactors. Previous studies revealed that advanced W with ultrafine grains and nanostructures might be able to address these problems. However, K-doped W, a rapidly developed material for PFMs, lacks a systematical summary. In this review, we firstly describe the powder metallurgy and plastic deformation for the preparation of WK. Then, the mechanical properties of WK and thermal shock resistance results are reviewed. Important issues such as irradiation damages from neutron, heavy ion, and plasma (H isotope or He) irradiation are also discussed. Hitherto, WK under irradiations shows comparable or even better performances compared with other counterparts such as ITER grade pure tungsten. This review could be benefitial to the future efforts of improving the ductility and irradiation tolerance of WK materials.

Pressure Dependence of Structural and Mechanical Properties of Single-Crystal Tungsten: A Molecular Dynamics Study

“…Due to the advantages of its high melting point, high heat conductivity, high sputtering resistance, and superior mechanical strength [1][2][3], W and its alloys have wide application potential in aerospace, electronics, and chemical and national defense military industries [4][5][6]. Notably, tungsten is considered to be one of the most likely candidates for plasma-facing material to be used in future nuclear fusion reactors and for target material in spallation facilities due to its outstanding comprehensive advantages [7][8][9][10].…”

Recent progress of radiation response in nanostructured tungsten for nuclear application

“…As a refractory transition metal with extremely high melting point, tungsten has been considered to be primary candidate for the plasma facing materials (PFMs) in the future fusion reactor [1]. Recently, many efforts have been done to fabricate tungsten-based materials with desired properties for advanced fission and fusion application by doping alloy elements [2][3][4][5][6] or dispersoid strengthening [7][8][9][10]. Tungsten-based PFMs will be directly exposed to 10-10 4 MeV plasma and 14.1 MeV neutron radiation in the fusion reactor [11][12][13].…”

The Mechanism of Joint Reduction of MoO3 and CuO by Combined Mg/C Reducer at High Heating Rates

“…Plasma facing materials (PFMs) build the keystructural components for the controlled nuclear fusion engineering pretending to be the basic source of energy for mankind in the 21st century [1,2]. Few refractory metals are nominated as potential candidates for PFMs armors simultaneously possessing high melting temperature, high thermal conductivity, thermal fatigue, low vapor pressure and low sputtering erosion yield (W, Mo and their multicomponent alloys) [1][2][3]. Copper is a heat-sink component for nuclear fusion devices due to its good thermal conductivity [3].…”