Optimization and characterization of tungsten steel joints for the plasma facing wall using different coating technologies including FGM techniques
Project ID:WP14-ER-01/FZJ-10
Period:Jan 01, 2014 - Dec 31, 2014
Recipient - coordinatorInstitute of Plasma Physics, Czech Academy of Sciences, Prague
Principal Investigator:Ing. Jiří Matějíček, Ph.D.
Co-recepient(s) / PI(s):Forschungszentrum Jlich GmbH -- Thomas Weber
Co-investigators from IPPM. Vilémová

Aims of the project: Tungsten coatings represent a viable solution for the manufacture of the plasma facing first wall material in future fusion devices (such as DEMO). Thereby, reduced activation ferritic martensitic (RAFM) steels are candidate materials for supporting structures and breeding blankets. For the successful outcome of the joining between tungsten and steel, an appropriate interlayer must be inserted in order to limit the thermal mismatch between both materials. In several studies tungsten steel joints either by an interlayer or by functionally graded material (FGM) have been produced. The used production methods were vacuum plasma spraying (VPS), atmospheric plasma spraying (APS), physical vapour deposition (PVD), spark plasma sintering (SPS), pulse plasma sintering (PPS), hot pressing and diffusion bonding. These preliminary experiments have shown the feasibility; however, the performance under severe loading scenarios still needs to be improved. In the frame of the Enabling Research Program two methods, thermal spraying and PVD, are foreseen for the production of functionally graded samples, which shall show their potential in high heat flux tests. Based on the past experience, the production of the coatings will be optimized.