【摘要】 研究了ＰＺＴ压电陶瓷铁电相变前后的断裂韧性和强度．分析了极化电场与外应力的相对取向对力学性能的影响．探讨了力学性能与极化层导致的畴转向和显微结构变化之间的关系．结果表明，断裂韧性和强度都随着温度的升高而下降至居里点处的低限值，然后略有回升．由于铁电相的热、弹性各向异性引起的内应力和极化残余应力，以及表面应力等的存在，强度比韧性随温度变化的幅度更陡．更多还原

【Abstract】 The fracture toughness and strength of PZT piezoelectric ceramics before and after ferroelectric phase transformation have been investigated. The influence of the electric field direction of polarization in regard to the applied stress on the mechanical properties has been analysed. The relation of mechanical behaviours to both the domain reorientation and the change in microstructures resulted from polarization and variation of temperature has also been researched. It has been shown that both the fracture toughness and strength decrease with the increase of temperature down to the minimum at the curie point and then increase lightly. Because of the presence of internal stress resulted from thermal-elastic anisotropy and remnant polarization of ferroelectric phase, as well as the presence of residual surface stress, the amplitude of the change in strength is more sharp, in comparison with those of the change in fracture toughness.更多还原