Recent progress in the assessment of irradiation effects for in-vessel fusion materials: tungsten and copper alloys

Abstract

The present contribution highlights results of the recent irradiation campaigns applied to screen mechanical properties of advanced tungsten and copper-based materials – main candidates for the application in the plasma-facing components (PFC) in the European DEMO, which has also been presented at 28th IAEA Fusion Energy Conference. The main challenges in the formulated irradiation programme were linked to: (I) assessment of the ductile-to-brittle transition temperature (DBTT) of newly developed tungsten-based materials; (ii) investigation of an industrial pure tungsten grade under high temperature irradiation, reflecting operational conditions in the high flux divertor region; (iii) assessment of the high temperature strength of CuCrZr-based alloys and composites developed to enable the extension of the operational window for the heat sink materials. The development and choice of the advanced materials is driven naturally by the need to extend the operation temperature/fluence window thereby enlarging the design space for PFCs. The obtained results helped identifying the prospective tungsten and copper-based material grades as well as yielded a number of unexpected results pointing at severe degradation of the mechanical properties due to the irradiation. The results are discussed along with the highlights of the microstructural examination. An outlook for near future investigations involving in-depth post-irradiation examination and further irradiation campaigns is provided.

Demonstrating tungsten fiber-reinforced porous-matrix tungsten composites for future fusion application

“…Our previous work demonstrated the much higher fracture toughness of W f /W compared to pure W [1], especially after neutron irradiation [49]. The present work further studies the performance of the developed PoMa-W f /W materials under fusion-relevant exposure conditions.…”

Effect of potassium bubbles on the thermal shock fatigue behavior of large-volume potassium-doped tungsten alloy

“…Hence, all kinds of W-based alloys were developed to improve the tensile strength and decrease the DBTT, such as carbides [12,13], oxides [14,15], dispersion strengthened W, W-vanadium [16], W-rhenium [17], potassium-doped W (W-K) alloys [18,19], etc. Among them, W-K alloys have been deemed to be one of the most potential PFMs because it can simultaneously improve the mechanical properties [20] and neutron irradiation resistance [21]. For example, the mechanical and neutron irradiation properties of W-K alloys have been extensively studied by Fukuda et al [22,23] and Nogami et al [24][25][26][27].…”

Sustainable New Technology for the Improvement of Metallic Materials for Future Energy Applications

“…SiC composites [31] W and W-based alloys [184][185][186] Cu-based alloys [186] Pb-Al alloy [187,188] HEA [189] Mo-based alloys [184] Nb-based alloy [184] V-based alloy [184] C-fiber components [190] Structural and insulating application, joints, and filaments [30,31] Table 3. Cont.…”