含孔隙PZT铁电陶瓷的单轴压缩力学响应研究

发布时间：2018-05-04 02:49

本文选题：PZT95/5铁电陶瓷 + 孔隙率　；参考：《宁波大学》2014年硕士论文

【摘要】：高锆系Pb(Zr0.95Ti0.05)O3(PZT 95/5)铁电陶瓷材料是铁电相和反铁电相共存的一类铁电陶瓷,具有非常优良的储能特性。在冲击载荷加载下,极化后已储存大量束缚电荷的PZT95/5铁电陶瓷会在极短时间内发生菱方铁电相到正交反铁电相相变而去极化,从而释放出储存的电荷,因此可以用于制备小巧的脉冲能源装置、爆电起爆装置等。本文结合数字散斑技术(DIC)对不同孔隙含量的PZT95/5未极化与极化铁电陶瓷进行准静态单轴压缩、动态单轴压缩(SHPB)实验,研究不同孔隙含量对材料力学性能的影响。1)准静态单轴压缩实验下未极化PZT95/5铁电陶瓷与极化PZT95/5铁电陶瓷的弹性模量、压缩强度、断裂应变基本相同,除了断裂应变不受孔隙率变化影响外,其它均随孔隙率的增大而下降。根据体积不变原理分析得到了未极化、极化PZT95/5的畴变起始点与相变起始点。其中,未极化与极化PZT95/5的畴变压力、相变压力均随孔隙率增大而下降。未极化PZT95/5畴变压力高于极化PZT95/5的畴变压力,而两者的相变压力恰恰相反,随着孔隙率的增大两者的差距逐渐缩小,在孔隙率为18%左右时基本相同。2)动态单轴压缩实验下通过时间与体积应变关系曲线间接得到了未极化、极化PZT95/5铁电陶瓷不同孔隙率下的相变起始点。未极化PZT95/5的压缩强度、断裂应变、畴变压力、相变压力均随孔隙率的增加而下降。极化PZT95/5的压缩强度、畴变压力、相变压力随着孔隙率的增加而下降,而断裂应变在孔隙率小于11%时基本保持不变,当孔隙率大于11%后随孔隙率增大而减小。未极化PZT95/5与极化PZT95/5的压缩强度在孔隙率小于11%时几乎相同,而当孔隙率大于11%后未极化PZT95/5的压缩强度要高于极化PZT95/5的压缩强度。未极化PZT95/5与极化PZT95/5的断裂应变在孔隙率小于13%时几乎相同,而当孔隙率大于13%后未极化PZT95/5的断裂应变要高于极化PZT95/5的断裂应变。未极化PZT95/5的畴变压力高于极化PZT95/5的畴变压力,而两者的相变压力大致相同。3)比较了动态与准静态加载下不同孔隙率对未极化、极化PZT95/5铁电陶瓷力学性能的影响。准静态下未极化PZT95/5的压缩强度与动态下未极化PZT95/5的压缩强度基本保持一致。在孔隙率为11%左右时准静态下极化PZT95/5的压缩强度与动态下的压缩强度基本相同,而在其余孔隙率时准静态下极化PZT95/5的压缩强度均高于动态下极化PZT95/5的压缩强度。准静态下未极化与极化PZT95/5的断裂应变均高于各自在动态下的断裂应变。准静态下未极化与极化PZT95/5的畴变压力均高于各自在动态下的畴变压力。准静态下极化PZT95/5的相变压力与动态下极化PZT95/5的相变压力几乎相同。动态下未极化PZT95/5的相变压力高于准静态下未极化PZT95/5的相变压力。4)构建了PZT95/5铁电陶瓷在准静态单轴压缩下考虑不同孔隙率影响的非线性纯力学本构。本构方程包括铁电相、铁电-反铁电相共存、反铁电相三个阶段,并对实验数据进行了拟合,获得了本构参数。
[Abstract]:The high zirconium Pb (Zr0.95Ti0.05) O3 (PZT 95/5) ferroelectric ceramics are ferroelectric ceramics which coexist with the ferroelectric phase and antiferroelectric phase, and have excellent energy storage properties. Under the load loading, the PZT95/5 ferroelectric ceramics, which have stored a large amount of bound charge after the polarization, will have the phase transition of the rhombus ferroelectric phase to the orthogonal antiferroelectric phase in the very short time. Depolarization, thus releasing the stored charge, can be used to prepare small pulse energy devices, detonating devices and so on. In this paper, the PZT95/5 unpolarized and polarized ferroelectric ceramics with different pore content are subjected to quasi static uniaxial compression and dynamic uniaxial compression (SHPB) experiments with different pore content, and the different pore content pairs are studied by using digital speckle technique (DIC). .1) the modulus of elasticity, compressive strength and fracture strain of unpolarized PZT95/5 ferroelectric ceramics and polarization PZT95/5 ferroelectric ceramics are basically the same under quasi static uniaxial compression test. Except the fracture strain is not affected by the change of porosity, the others decrease with the increase of porosity. The analysis is obtained by the principle of volume invariance. The domain change starting point and the starting point of the polarization PZT95/5 are not polarized, in which the pressure of the domain change of the unpolarized and polarized PZT95/5 decreases with the increase of the porosity. The unpolarized PZT95/5 domain pressure is higher than the domain change pressure of the polarization PZT95/5, and the phase transition pressure is exactly opposite, and the gap gradually decreases with the increase of the porosity. When the porosity is about 18%, it is basically the same.2). Under the dynamic uniaxial compression test, the starting point of unpolarized, polarized PZT95/5 ferroelectric ceramics under different porosity is indirectly obtained under the dynamic uniaxial compression test. The compressive strength of unpolarized PZT95/5, the fracture strain, the domain change pressure, and the phase change pressure are all under the increase of porosity. The compression strength, domain change pressure and phase change pressure decrease with the increase of porosity, while the fracture strain is basically unchanged when the porosity is less than 11%. When the porosity is greater than 11%, the porosity decreases with the porosity increasing. The compressive strength of unpolarized PZT95/5 and polarization PZT95/5 is almost the same when porosity is less than 11%, and when porosity is less than 11%. The compression strength of unpolarized PZT95/5 after the rate of more than 11% is higher than the compression strength of polarization PZT95/5. The fracture strain of unpolarized PZT95/5 and polarization PZT95/5 is almost the same when the porosity is less than 13%, while the fracture strain of unpolarized PZT95/5 is higher than the polarization strain of polarization PZT95/5 when the porosity is greater than 13%. The domain change pressure of unpolarized PZT95/5 is higher. The domain change pressure of polarization PZT95/5, while the phase transition pressure is approximately.3), compares the effects of different porosity on the mechanical properties of unpolarized and polarized PZT95/5 ferroelectric ceramics under dynamic and quasi-static loading. The compressive strength of unpolarized PZT95/5 under quasi static condition is basically consistent with the compressive strength of unpolarized PZT95/5 under dynamic conditions. The compressive strength of the quasi static lower polarization PZT95/5 is almost the same as the dynamic compressive strength at about 11%, while the compressive strength of the quasi-static lower polarization PZT95/5 is higher than that of the dynamic lower polarization PZT95/5 at the rest of the porosity. The fracture strain of the unpolarized and polarizing PZT95/5 under quasi static state is higher than that under the dynamic fracture stress. The domain variation pressure of the unpolarized and polarizing PZT95/5 under quasi static state is higher than that of the domain variation under the dynamic state. The phase transition pressure of the quasi static down polarization PZT95/5 is almost the same as that of the dynamic lower polarization PZT95/5. The phase transition pressure of the unpolarized PZT95/5 is higher than the phase transition pressure.4 under the quasi static unpolarized PZT95/5. The phase transition pressure of the dynamic under polarization is higher than that of the quasi static PZT95/5. The constitutive equations include ferroelectric phase, ferroelectric antiferroelectric phase coexistence and antiferroelectric phase three stages, and the constitutive parameters are obtained. The constitutive equation of 5 Ferroelectric Ceramics is considered under quasi static uniaxial compression.

【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM28

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