TY - JOUR
T1 - Self-castellation of tungsten monoblock under high heat flux loading and impact of material properties
AU - Panayotis, Stephanie
AU - Hirai, Takeshi
AU - Barabash, Valdimir
AU - Durocher, Alain
AU - Escourbiac, F.
AU - Linke, Jochen
AU - Loewenhoff, Thorsten
AU - Merola, Mario
AU - Pintsuk, Gerald
AU - Uytdenhouwen, Inge
AU - Wirtz, Marius
N1 - Score=10
PY - 2016/12/27
Y1 - 2016/12/27
N2 - In the full-tungsten divertor qualification program at ITER Organization, macro-cracks, so called self-castellation were found in a fraction of tungsten monoblocks during cyclic high heat flux loading at 20MW/m2. The number of monoblocks with macro-cracks varied with the tungsten products used as armour material. In order to understand correlation between the macro-crack appearance and W properties, an activity to characterize W monoblock materials was launched at the IO. The outcome highlighted that the higher the recrystallization resistance, the lower the number of cracks detected during high heat flux tests. Thermo-mechanical finite element modelling demonstrated that the maximum surface temperature ranges from 1800 °C to 2200 °C and in this range recrystallization of tungsten occurred. Furthermore, it indicated that loss of strength due to recrystallization is responsible for the development of macro-cracks in the tungsten monoblock.
AB - In the full-tungsten divertor qualification program at ITER Organization, macro-cracks, so called self-castellation were found in a fraction of tungsten monoblocks during cyclic high heat flux loading at 20MW/m2. The number of monoblocks with macro-cracks varied with the tungsten products used as armour material. In order to understand correlation between the macro-crack appearance and W properties, an activity to characterize W monoblock materials was launched at the IO. The outcome highlighted that the higher the recrystallization resistance, the lower the number of cracks detected during high heat flux tests. Thermo-mechanical finite element modelling demonstrated that the maximum surface temperature ranges from 1800 °C to 2200 °C and in this range recrystallization of tungsten occurred. Furthermore, it indicated that loss of strength due to recrystallization is responsible for the development of macro-cracks in the tungsten monoblock.
KW - Fracture
KW - Tungsten
KW - ITER
KW - high heat flux
KW - Divertor
KW - recrystallization
UR - http://ecm.sckcen.be/OTCS/llisapi.dll/open/25233900
U2 - 10.1016/j.nme.2016.10.025
DO - 10.1016/j.nme.2016.10.025
M3 - Article
SN - 2352-1791
SP - 1
EP - 5
JO - Nuclear Materials and Energy
JF - Nuclear Materials and Energy
ER -