Fracture behaviour of tungsten–vanadium and tungsten–tantalum alloys and composites

Recent progress in R&D on tungsten alloys for divertor structural and plasma facing materials

“…Three-point bending (3PB) tests showed that the material is brittle at 298 K and ductile at 673 K and above. The bending stresses at fracture range from ~1.3 GPa at 298 K down to ~580 MPa at 1273 K [19]. This was confirmed by tensile tests that showed that the material is fully ductile in the investigated temperature range of 673K-1273K; the total elongation is between 4% and 10% ( …”

“…However, alloying with Ta and V does not improve DBTT or the Charpy energy (Fig. 2); moreover, the fracture toughness of W-Ta alloys decreases with increasing Ta content [19]. Recent studies with Ti, which should be verified using a different fabrication route, have not led to promising results [20,21].…”

Recent progress in research on tungsten materials for nuclear fusion applications in Europe

“…It is known that tungsten features an anisotropic fracture behaviour in the case of the presence of elongated grains, e.g., after rolling, forging and deformation by HPT [55,56]. Additionally, the fracture resistance may increase with crack propagation, which implies that it is not always possible to characterize the material's toughness with one single value such as plane strain fracture toughness K IC or critical energy release rate G IC .…”

Enhanced toughness and stable crack propagation in a novel tungsten fibre-reinforced tungsten composite produced by chemical vapour infiltration

“…The resulting notch radius is approximately 10 µm. Finally a focused ion beam (FIB) is used to produce two small adjoining pockets at the notch tip which act as dedicated crack initiation points [25]. The overall notch depth is a = 990 µm, which is approximately 30% of the sample height.…”