多孔极化PZT95/5铁电陶瓷单轴压缩力学响应与放电特性

采用添加造孔剂的方法制备了四种不同孔隙率PZT95/5铁电陶瓷，对其进行电场极化，随后开展了准静态单轴压缩实验，讨论了畴变、相变以及孔隙率对极化PZT95/5铁电陶瓷的力学响应与放电特性的影响. 研究结果表明：(1)多孔极化PZT95/5铁电陶瓷非线性力学响应行为主要归因于畴变和相变的共同作用，与内部孔洞变形和坍塌基本无关；(2) 在准静态单轴压缩下极化PZT95/5铁电陶瓷的去极化机制是畴变和相变的共同作用；(3) 孔隙率对极化PZT95/5铁电陶瓷的弹性模量、压缩强度有明显的影响，而对断裂应变的影响较小；(4)极化PZT95/5铁电陶瓷畴变和相变开始的临界应力都随着孔隙率的增大而线性衰减，但相变开始的临界体积应变却不依赖孔隙率；(5)极化PZT95/5铁电陶瓷电荷饱和释放量随着孔隙率呈线性减小，但孔隙率对电荷释放速率基本没有影响。

Mechanical Properties and Depoling of Porous Poled PZT95/5 Ferroelectric Ceramics under Uniaxial Compression

Four kinds of poled lead zirconate titanate (PZT95/5) ferroelectric ceramics were fabricated with a range of different porosity levels by systematic additions of added pore formers. The mechanical behavior, domian switching, phase transformation and depoling behavior of porous poled PZT95/5 ferroelectric ceramics were investigated as a function of porosity. The unlinear deformation mechanism of porous poled PZT95/5 ferroelectric ceramics is attributed to the domian switching and phase transformation processes and not related to the deformation and collapse of voids. The depolarization mechanism of porous poled PZT95/5 ferroelectric ceramics is caused by both domian-reorientation and phase transformation. The elastic modulus and fracture strength the porous poled PZT95/5 ferroelectric ceramics are decreased with the porosities, but the fracture strain is independent on the porosities.Critical stresses of the domian switching and phase transformation and the peak of polarization released of poled PZT95/5 ferroelectric ceramics linearly decrease with increasing porosities, but the critical volumetric strain needed for phase transformation and the rate of polarization released are independent on the porosities.