THE STRUCTURE OF THE REACTION ZONE IN Si_3N_4-Fe DIFFUSION COUPLES

摘要

Diffusion couples of silicon nitride ceramics and iron alloys are used to assess the reactivity and interfacial evolution of this ceramic-metal system. Diffusion tests are carried out under an argon or vacuum atmosphere for temperatures of 1150℃ and 1190℃and reaction times from 5h to 15h. The structure of the reaction zone on the ceramic side of the couples is characterised by SEM/EDS and TEM/EDS analyses. Reaction products from the ceramic decomposition depend on the Si_3N_4 sintering additive composition and the carbon and chromium content of the iron alloys.