Speaker
Javier de Prado
(Materials Science and Engineering Area)
Description
Development of new materials is one of the key for the construction of the new fusion power plant (DEMO). The selected materials have to fulfill several requirements such as standing the conditions that takes place in the core (high neutron flux and temperatures close to 1200 ºC) and low activation rate.
Several techniques have been proposed to join the different parts of the first wall components such as brazing, diffusion bonding and laser welding. Among them, high temperature brazing seems to be the most suitable technique due to its limited effect on the base material properties. Cu-20Ti filler composition has been demonstrated to fulfill all the joint requirements to be used in the first wall of fusion reactors [1]. The filler is made of a mixture of pure Cu and Ti powders. However, the usage of alloyed powders instead of pure powders provides some advantages.
Results of W-EUROFER joints using Cu-20Ti alloyed powders have shown the consecution of high quality joints. The filler melts in a reduced time compared to previous one because the as-received powders already have the Cu-20Ti composition. This fact enhances the spreading capabilities of the filler at the joint clearance and opens the possibility of developing the joint with lower brazing temperatures. Moreover, the use of alloyed powder allows working with higher heating rates (up to 6 time higher), saving hours of heating process. The improvement could benefit both for reducing diffusion effects in EUROFER and improving productivity of the brazing procedure.
The characterization of the joint has been done by means of SEM and optic microscope for the microstructural characterization and shear strength and Vickers microharness tests for mechanical characterization.
[1] J. de Prado et al. Development of brazing process for W– EUROFER joints using Cu-based fillers. Phys. Scr. T167 (2016) 014022 (5pp).
Co-authors
Alejandro Urena
(Materials Science and Engineering Area, Rey Juan Carlos University, C/ Tulipan S/N 28933 Mostoles (Madrid), Spain)
Javier de Prado
(Materials Science and Engineering Area, Rey Juan Carlos University, C/ Tulipan S/N 28933 Mostoles (Madrid), Spain)
Maria Sanchez
(Materials Science and Engineering Area, Rey Juan Carlos University, C/ Tulipan S/N 28933 Mostoles (Madrid), Spain)
