Thermal conductivity and dielectric property of hot-pressing sintered AlN-BN ceramic composites

A study was conducted of the effects of sintering temperature and CaF2 additives on densification, microstructure, dielectric property and thermal conductivity of AlN-BN composites. Increasing sintering temperature and CaF2 contents help to improve the densification, thermal conductivity, and purification of the grain boundaries. Thermal conductivity value reached 110 W m(-1) K-1 for AlN-BN composites with 3 wt.% CaF2 and sintered at 1850 degrees C. Increasing sintering temperature decreases relative dielectric constant and tan S. The increase in CaF2 content increases relative dielectric constant and decreases tan delta. Relative dielectric constants values were between 7.29 and 7.64 and dielectric loss tangent values ranged from 6.36 to 7.83 x 10(-4) at 1 MHz. (C) 2007 Elsevier Ltd and Techna Group S.r.l. All rights reserved.