Reactive metallic layers produced on AlN, Si₃N₄ and SiC ceramics

Abstract

The paper presents the results of studies on the joining of non-oxide ceramics with copper with the use of intermediary metallic layers. AlN ceramics was covered with Mo, Mn, FeSi, Ti intermediary layers, Si₃N₄ ceramics – with Cu, Mn, Ti layers, and SiC ceramics – with Cr, TiCu layers. Although the individual metallic layers were synthesized under different conditions, all the structures contained barrier layers formed during the synthesis process. With the AlN and Si₃N₄ ceramics, the barrier layer was composed of TiN, which was well wetted by the metallic and oxide phases. With the SiC ceramics, the role of the barrier layer was played by the Ti₃SiC₂ phase. The thickness of the barrier layers of both types (TiN, Ti₃SiC) was about 1 μm. They were well wetted by the metallic solders, coherent with the ceramic surface, and, within the brazed multi-layer joints, they constituted a continuous microstructure.