화학공학소재연구정보센터
Journal of the American Ceramic Society, Vol.103, No.10, 5567-5572, 2020
Improved thermal conductivity of beta-Si(3)N(4)ceramics by lowering SiO2/Y(2)O(3)ratio using YH(2)as sintering additive
A two-step sintering process was conducted to produce beta-Si(3)N(4)ceramics with high thermal conductivity. During the first step, native SiO(2)was eliminated, and Y(2)O(3)was in situ generated by a metal hydride reduction process, resulting in a high Y2O3/SiO(2)ratio. The substitution YH(2)for Y(2)O(3)endow Si(3)N(4)ceramics with an increase of 29% in thermal conductivity from 95.3 to 123 W m(-1) K(-1)after sintered at 1900 degrees C for 12 hours despite an inferior sinterability. This was primarily attributed to the purified enlarged grains, devitrified grain boundary phase, and reduced lattice oxygen content in the YH2-MgO-doped material.