Examination of Be//Cu joints in hipped Be tiles by using Ion Beam Analysis methods

Be has a tendency to form particularly brittle intermetallics with Cu and a lot of other elements. Insertion of interlayers may be a solution to increase bond quality. Ion Beam Analysis (IBA) methods have been considered together with scanning electron microscopy (SEM) and electron back-scattering diffraction (EBSD) as complementary techniques for the characterization of the Be//Cu junction. The following work aims at demonstrating how such techniques (used in micro-beam mode) coupled with SEM/EBSD data, can bring valuable information in this area. Interlayer-free mock-ups reveal intermetallics which are mainly BeCu (apparently mixed with lower quantities of BeCu2 compound). While Cr or Ti interlayers seem to behave as good Be diffusion barriers preventing the formation of BeCu, they strongly interact with Cu to form CuTi2 or Cr2Ti intermetallics. In the case of Cr, Be seems to be incorporated into the Cr layer.