The electrical conductivity was providing to structural ceramics by controlling the grain boundary phase. We focused on grain boundary phase of Si3N4 ceramics, which can be considered as infinite network for conducting path. The constituents of the conductive path in the sintered samples must be formed as a glassy grain boundary phase during sintering by melting. As the glassy phase, which does not have the particle shape, possesses the radius Rd around zero, it can be expected the critical volume fraction Φc is abruptly reduced compared with particle dispersion method generally used. In this study, we investigated the correlationship of microstructure, sinterability, mechanical properties and ionic conductivity of Si3N4 ceramics with alkali alminosilicate grain boundary phase. The result that ionic conductive Si 3N4 ceramics were fabricated by Pulse Electric Current Sintering (PECS) for controlled composition of grain boundary phase. Fabricated materials by PECS method was indicated very fine microstructure. The Si 3N4 ceramics had glassy phases between two matrix grains and in multiple grain boundaries, and showed three orders of magnitude higher conductivity than general silicon nitride ceramic.
|出版ステータス||Published - 2005|
|イベント||106th Annual Meeting of the American Ceramic Society - Indianapolis, IN, United States|
継続期間: 2004 4月 18 → 2004 4月 21
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