Low-temperature spark plasma sintering of alumina by using SiC molding set

Fully dense transparent alumina is obtained after spark plasma sintering at 1000 degrees C by using the electrically conductive SiC molding set. Compared to the conventional graphite set, the new mold material lowered the sintering temperature by 150 degrees C for full densification. The SiC set has a lower electrical conductivity than that of the graphite set, which resulted in higher electric field during heating. The enhanced densification is attributed to the high electric field. In this study, the effects of the electric field and the heating rate on the densification of alumina are examined with the SiC molding set, and compared to the results with the graphite set. (C) 2016 The Ceramic Society of Japan. All rights reserved.