Stability of beryllium coatings deposited on carbon under annealing up to 1073 K

Abstract

Chemical reactions involving co-deposits in plasma facing components will occur under heat loads. Previous experiments in the Be-C-O system evidenced that compound formation may induce by itself the peel-off of deposits when C films are annealed in vacuum due to the simultaneous formation and mixing of Be2C and BeO. The present experiment investigates the reverse case, where Be films are deposited on graphite and annealed up to 1073 K. The delamination mechanism also exist and it is initialise at 973 K. However, it remains scarce since the carbide and oxide phases grow preferentially at different depths. The experiment points C as a source of dust in presence of Be in operative scenarious. Phase formation was followed by ion beam analysis, X-ray diffraction and electron microscopy.