Grain Boundary Behavior and Heat Treatment Effect of AlN Ceramics Prepared from Al-isopropoxide

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J. Korean Ceram. Soc. > Volume 28(4); 1991 > Article

Journal of the Korean Ceramic Society 1991;28(4): 269.

Al-isopropoxide로부터 AlN 소결체의 입계상 거동 및 열처리 효과

황해진, 이홍림

연세대학교 공과대학 요업공학과

Grain Boundary Behavior and Heat Treatment Effect of AlN Ceramics Prepared from Al-isopropoxide

ABSTRACT

Fine AlN powder was synthesized by carbothermal reduction and nitridation of alumimun hydroxide prepared from Al-isopropoxide. AlN ceramics with Y2O3 and CaO were prepared by hot-pressing under the pressure of 30 MPa at 180$0^{circ}C$ for 1 h in N2 atmosphere. Grain boundary behavior and purification mechanism of AlN lattice were examined by heat treatment of AlN ceramics at 185$0^{circ}C$ for 1-6 h in N2 atmosphere. AlN ceramics without sintering additives showed poor sinterability. However, Y2O3-doped and CaO-doped AlN ceramics were fully densified nearly to theoretical density. As the heat treatment time increased, c-axis lattice parameter increased. This is attributed to the removal of Al2O3 in AlN lattice. This purification effect of AlN attice depended upon the quantity of secondary oxide phase in the inintial stage of heat treatment and the heat treatment time.