TY  - JOUR
AU  - Tweer, Jannik
AU  - Day, Robin
AU  - Derra, Thomas
AU  - Dorow-Gerspach, Daniel
AU  - Loewenhoff, Thorsten
AU  - Wirtz, Marius
AU  - Linsmeier, Christian
AU  - Bergs, Thomas
AU  - Natour, Ghaleb
TI  - Initial experiments to regenerate the surface of plasma-facing components by wire-based laser metal deposition
JO  - Nuclear materials and energy
VL  - 38
SN  - 2352-1791
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - FZJ-2024-00728
SP  - 101577 -
PY  - 2024
AB  - Plasma-facing components (PFC) in nuclear fusion reactors are exposed to demanding conditions during operation. The combination of thermal loads, plasma exposure as well as neutron induced damage and activation limits the number of materials suitable for this application. Due to its properties, tungsten (W) is foreseen as plasma-facing material (PFM) for the future DEMOnstration power plant. It is considered suitable due to its exceptionally high melting point, excellent thermal conductivity, low tritium retention and low erosion resistance during plasma exposure. But even tungsten armored PFCs have a limited lifetime due to, among other factors, surface erosion and the resulting thickness reduction of the armor material.In-situ local deposition of tungsten by means of additive manufacturing (AM) could counteract surface erosion and thus increase the service life span of PFCs. After evaluation of the potential AM processes qualified for this task, the wire-based laser metal deposition (LMD-w) process was selected as the most suitable process. First trials were conducted to examine if it is possible to reliably deposit tungsten onto tungsten substrate using the LMD-w process. In these first studies, single welding beads were generated, and in later experiments, entire layers were created from several welding beads which are arranged next to each other. To ensure reproducibility of the results, the substrate temperature was kept constant. Further experiments aimed at the elimination or minimization of problems such as oxidation, occurrence of balling defects, porosity, cracking, surface waviness and insufficient connection to the substrate. To increase the welding bead quality, the input parameters like laser power, deposition velocity, wire feed rate, inert gas flow, as well as the wire position were optimized. Furthermore, stacking of several layers, as well as the remelting of an already created layer, were carried out and investigated. This study represents the first steps in testing the feasibility of an in-situ surface regeneration concept for PFCs.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001154211000001
DO  - DOI:10.1016/j.nme.2023.101577
UR  - https://juser.fz-juelich.de/record/1021431
ER  -