Dependence of Strength and Crack Growth of PZT Ceramics on Poling Strength

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J. Korean Ceram. Soc. > Volume 34(8); 1997 > Article

Journal of the Korean Ceramic Society 1997;34(8): 877.

Poling 강도 변화에 따르는 PZT 세라믹스의 강도와 균열성장 의존성

이홍림, 권종오, 한봉석

연세대학교 세라믹공학과

Dependence of Strength and Crack Growth of PZT Ceramics on Poling Strength

ABSTRACT

The dependence of strength, crack growth, fracture mode and degree of domain rearrangement of PZT ceramics on poling strength were studied. The PZT [(Pb0.94Sr0.06)(Zr0.46Ti0.54)O3+Nb(trace)] specimens were poled at 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 kv/mm, and the strength of the specimens was measured by 3 point flexure system. The bending strength of the specimen decreased in different modes according to the bending directions; xz, zx and yz plane direction with x axis of the poling direction in Cartesian coordinate system. The strength differences between the directions increased as the poling strength increased. The fracture mode transferred to intergranular fracture mode from transgranular one as the poling strength increased. The mechanical breakdown occurred when the poling strength higher than 3 kV/mm was applied to the specimen. It was observed that the crack length increased in the normal direction to the poling direction, however, decreased in the parallel direction to the poling direction when the poled PZT specimen was indented by the Vickers indenter. However, the crack produced by indentation continuously was continuously increased little by little after indentation on the specimen. The domain rearrangement occurred as the poling strength increased and the domains were rearranged more effectively when the electric field was continuously increased little by little.

Key words: PZT, Domain rearrangement, Poling, Crack growth, Electric field