Effect of annealing Atmosphere on the Piezoelectric and Mechanical Properties of PZT Ceramics

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J. Korean Ceram. Soc. > Volume 31(9); 1994 > Article

Journal of the Korean Ceramic Society 1994;31(9): 1037.

PZT 세라믹스이 압전 및 기계적 특성에 미치는 어닐링 분위기의 영향

임진호, 손준호, 김진호, 조상희

경북대학교 무기재료공학과

Effect of annealing Atmosphere on the Piezoelectric and Mechanical Properties of PZT Ceramics

ABSTRACT

The effects of annealing atmosphere and temperature on piezoelectricity (k33) and the mechanical strength of machined PZT was studied. Morphotropic Nb-doped PZT was sintered, machined to a rod and then annealed between 80$0^{circ}C$ and 100$0^{circ}C$ in air, PbZrO3, and CuO atmospheres respectively. In air or PbZrO3 atmosphere, the compressive strength of Nb-doped PZT increased by 12% with little change in k33 irrespective of annealing temperature. In CuO atmosphere, on the other hand, the compressive strength increased by 20% with little change in k33 at 80$0^{circ}C$ but both turned to significant decrease above 90$0^{circ}C$. The examination of the phase distribution and microstructure beneath the surface of CuO-treated PZT revealed that the changes in compressive strength and k33 are closely related to the reaction between PZT and vaporized CuO:liquid PbO precipitated in shallow surface region by the substitution of Cu to Pb sites enhances the decrease in microcracks and the surface roughness at 80$0^{circ}C$ ; rapid evaporation of precipitated PbO expands a porous region of changed composition into the bulk above 90$0^{circ}C$.