Fracture-mechanical behaviour of ITER grade tungsten subjected to three different rolling processes

• Published in: Fusion engineering and design Vol. 184; p. 113300
• Main Authors: Gaganidze, E., Chauhan, A., Aktaa, J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2022; Elsevier Science Ltd
• Subjects: Cross rolling; Failure modes; Fracture mode; Fracture-toughness; Investigations; ITER grade tungsten; Machining; Mechanical properties; Orientation; Plates; Tungsten; ITER grade tungsten; Fracture-toughness; Fracture mode
• ISSN: 0920-3796; 1873-7196
• DOI: 10.1016/j.fusengdes.2022.113300

•Applied different rolling processes appear to have a minor effect on the DBTT.•Cross rolling leads to nearly no impact on the DBTT and to only minor reduction of the temperature for the onset of full crack blunting.•Fracture mechanism changed from prominently brittle fracture up to 500°C to onset of pronounced blunting and dimple formation at high temperatures for all investigated plates. We investigated the fracture-mechanical behaviour of three ITER grade tungsten plates subjected to different rolling processes. One plate was uniaxially rolled at a normal rolling ratio. The two other plates were subjected to cross rolling processes at normal and high rolling ratios. Two of the three plates were characterized for L-T and T-L orientations, whereas the plate subjected to the cross rolling at a normal rolling ratio was tested in the L-T orientation only. The DBTTs of the investigated plates determined via fracture-mechanical experiments were near 300°C, irrespective of the specimen machining directions. Marginally better fracture-mechanical behaviour was observed in the L-T orientation compared to T-L orientation for the uniaxially rolled plate. The plate subjected to the cross rolling process at the normal rolling ratio was found to have inferior fracture-mechanical behaviour. This manifested in the form of steep load drops in load-displacement curves, which persisted even at the highest test temperature of 800°C. Fractographic investigations revealed the governing failure modes of the investigated materials.