Furnace and laser methods of bonding metals to ceramics: interface investigation

Furnace and laser methods of direct bonding copper to industrial alumina in neatly inert atmospheres are investigated. Of specific interest is the int erface and its characterization. Lasers of different wavelengths are employ ed to heat the metal component for a sufficient time to create a metal-meta l oxide eutectic melt at the metal-ceramic interface. X-ray diffraction, tr ansmission electron microscopy and high-resolution transmission electron mi croscopy are used to investigate metal-ceramic interfaces. Samples heated i n a furnace and by laser beam were found to have a diffuse metal ceramic in terface. The electron diffraction patterns indicate the phase at the interf ace (Cu/alpha-Al2O3) is cubic with the CuAl2O4 crysrallographic structure. Samples heated by an excimer laser have a nano-sized grain structure in the top copper layer. (C) 2000 Elsevier Science S.A. All rights reserved.