Speaker
Simon Heuer
(Forschungszentrum Jülich GmbH)
Description
Future fusion reactors may exhibit first walls composed of a tungsten (W) armor, that is attached to a subjacent stainless steel (SS) structure. Joining these materials for the application at hand is challenging because the pulsed operation of TOKAMAK reactors induces thermo-mechanical stresses and strains at the W/SS interface due to differing materials properties. These cyclic loads will degrade the W/SS joint, eventually resulting in delamination of the armor, in which the number of endured cycles strongly depends on the type and quality of the W/SS bond. Current approaches focus on implementing a functionally graded (FG) interlayer between the W and the SS part. The FG composite exhibits a varying fractional W/SS composition along the interlayer height, thus re-distributing and reducing macroscopic loads, as compared to a direct W/SS joint.
In order to characterize FG interlayers, this contribution addresses the microstructure as well as thermal and mechanical properties of several W/SS compositions manufactured via Atmospheric Plasma Spraying (APS) and Electro Discharge Sintering (EDS). In this context the residual porosity, the formation of phases, thermal conductivities as well as thermal expansions, and the fracture toughness at temperatures ranging from room temperature to 300°C were investigated.
Co-authors
Andreas Mohr
(Ruhr-Universität Bochum, Chair of Materials Technology, 44780 Bochum, Germany)
Christian Linsmeier
(Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research, Partner of the Trilateral Euregio Cluster (TEC), 52425 Jülich, Germany)
Jiri Matejicek
(Institute of Plasma Physics, Department of Materials Engineering, 18200 Prague, Czech Republic)
Monika Vilemova
(Institute of Plasma Physics, Department of Materials Engineering, 18200 Prague, Czech Republic)
Simon Heuer
(Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research, Partner of the Trilateral Euregio Cluster (TEC), 52425 Jülich, Germany)
Thomas Weber
(Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research, Partner of the Trilateral Euregio Cluster (TEC), 52425 Jülich, Germany)
Tim Lienig
(Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research, Partner of the Trilateral Euregio Cluster (TEC), 52425 Jülich, Germany)
Werner Theisen
(Ruhr-Universität Bochum, Chair of Materials Technology, 44780 Bochum, Germany)
