Irradiation effects in tungsten—From surface effects to bulk mechanical properties. (March 2022)

• Record Type: Journal Article
• Authors: Riesch, J.; Feichtmayer, A.; Coenen, J.W.; Curzadd, B.; Gietl, H.; Höschen, T.; Manhard, A.; Schwarz-Selinger, T.; Neu, R.
• Is Part Of: Nuclear materials and energy. Volume 30(2022)
• Publication Date: 2022-03
• Subjects: Tungsten -- Wire -- Ion irradiation -- Tensile test -- Embrittlement -- Ductility; Nuclear energy -- Periodicals; Nuclear fuels -- Periodicals; Nuclear reactors -- Materials -- Periodicals; Radioactive substances -- Periodicals; 621.4833
• DOI: 10.1016/j.nme.2021.101093
• Languages: English
• ISSNs: 2352-1791

Abstract

Abstract: Advanced materials such as tungsten fibre-reinforced composites allow to overcome severe weaknesses of the baseline materials for plasma-facing components — copper and tungsten. The effect of the fusion environment on the mechanical properties of these materials, e.g. the embrittlement by neutron irradiation, plays a key role for the development of future fusion reactors. To simulate this effect, high-energy ions are used as a substitute for the displacement damage by neutrons. We propose the use of very fine tungsten wire as a possibility of studying the influence of irradiation damage on the mechanical properties. This is possible as they allow full-depth irradiation of almost the entire volume despite the limited penetration depth of ions. Geometrical size effects are mitigated due to the nanoscale microstructure of the wire. In addition, similar wire is used in tungsten fibre-reinforced composites. Thus, the investigation of irradiated wire can directly be used for the prediction of the bulk composite properties. For the proof of this concept tungsten wire with a diameter of 16 μ m was electrochemically thinned to 5 μ m and irradiated with 20.5 MeV W 6 + ions. The mechanical properties were subsequently determined by macroscopic tensile testing. Irradiation to 0.3, 1 and 9 dpa did not lead to a change of the mechanical behaviour. Both strength and ductility, the latter indicated by the reduction of area, were similar to the as-fabricated state. Highlights: Tensile testing of ion-irradiated drawn tungsten wire with a diameter of 5 μ m. Small size allows irradiation of almost the entire volume. Size effects are mitigated due to nanoscale microstructure. Irradiation to 0.3 dpa, 1 dpa and 9 dpa by 20.5 MeV W 6 + ions. No change in strength and ductility due to irradiation.