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

Abstract

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 BeCu 2 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 CuTi 2 or Cr 2Ti intermetallics. In the case of Cr, Be seems to be incorporated into the Cr layer.