Properties of Al2O3-15v/o ZrO2(＋3m/o Y2O3) Powder Prepared by Co-Precipitation Method

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J. Korean Ceram. Soc. > Volume 26(2); 1989 > Article

Journal of the Korean Ceramic Society 1989;26(2): 210.

공침법으로 제조한 Al2O3-15v/o ZrO2(＋3m/o Y2O3)계 분말의 특성

홍기곤, 이홍림

연세대학교 공과대학 요업공학과

Properties of Al2O3-15v/o ZrO2(＋3m/o Y2O3) Powder Prepared by Co-Precipitation Method

ABSTRACT

The properties of the powder of Al2O3-15v/o ZrO2(＋3m/o Y2O3) system prepared by co-precipitation method at the pH values of 7, 9, 10 and 11 were investigated. Al2(SO4)3.18H2O, ZrOCl2.8H2O and YCl3.6H2O were used as starting materials and NH4OH as a precipitation agent. Zirconium hydroxide decreased the specific surface area of aluminum hydroxide of AlOOH type, while increased the specific surface area of aluminum hydroxide of Al(OH)3 type, and formed co-network structure of Al-O-Zr type with the aluminum hydroxides. The rate of transition to $alpha$-Al2O3 from co-precipitated materials occurred in the order of 7≒10, 9 and 11 of pH values. Al2O3 and ZrO2 interacted to bring about coupled grain growth, and the growth of ZrO2 crystallite size rapidly occurred within $theta$-Al2O3 matrix. Segregation did not occur in the system Al2O3-15v/o ZrO2(＋3m/o Y2O3) and Y2O3 acted as a stabilizer to ZrO2. The lattice strain of tetragonal ZrO2 was increased by the constraint effect of Al2O3 matrix.