Effect of Sm_2O_3 content on microstructure and thermal conductivity of Spark Plasma Sintered AlN ceramics

摘要

Dense aluminum nitride ceramics were prepared by Spark Plasma Sintering at a lower sintering temperature of 1700 deg C with Sm_2O_3 as sintering additives. The effect of Sm_2O_3 content on the density, phase composition, microstructure and thermal conductivity of A1N ceramics was investigated. The results showed that Spark Plasma Sintering could fabricate dense A1N ceramics with superior thermal properties in a very short time. Sm_2O_3 not only facilitated the densification via the liquid-phase sintering mechanism but also improved thermal conductivity by decreasing oxygen impurity. Thermal conductivity decreased with increasing amount of Sm_2O_3 and the highest thermal conductivity was obtained for the AlN ceramics with 2 wt. percent Sm_2O_3 content. During Spark Plasma Sintering process, only 2-3 wt. percent sintering additives was enough to fabricate dense AlN ceramics, and the microstructures played a key role in controlling the thermal conductivity of AlN ceramics.