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针对95氧化铝陶瓷薄弱的沿面耐压能力开展体掺杂改性实验研究,以95氧化铝陶瓷瓷料为基料,选择Cr2O3和MnCO3作为添加剂制备掺杂样品,并对陶瓷样品开展了性能参数测试及沿面耐压、体击穿、金属化等实验研究,探讨锰铬掺杂对陶瓷表面结构和性能的影响。 相似文献
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: 本文基于笔者近年来关于钛酸钡基无铅铁电陶瓷的研究结果, 阐述了B a ( T i 0. 9 9C o 0. 0 1) O3 -d 无铅铁电陶
瓷的综合型实验教学设计与实施. 该实验条件简单, 结果可靠, 涉及材料物理及相关技术等多方面内容, 是一类培养
大学生实验能力与创新能力的研究综合性实验. 相似文献
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介绍了一种基于纳米粉末真空烧结技术的新型固体激光材料——Yb:Y2O3多晶陶瓷的制备工艺、物理化学特性、能级结构和光谱特性,并与Yb:YAG单晶进行了对比.采用紧凑型有源镜激光器(CAMIL)的抽运方式,验证了Yb:Y2O3透明陶瓷的激光输出性能.在35W的最大抽运功率下,得到波长1078 nm,功率10.5 W 的连续激光输出,斜率效率达到37.5%.实验中还观察到激光输出波长随抽运功率增加而红移以及随输出耦合镜变化而漂移的现象.Yb:Y2O3多晶陶瓷是一种理想的激光材料,不仅具有与Yb:YAG单晶同样优秀的物理化学性能和光谱特性,而且其热导率和发射带宽约为Yb:YAG单晶的两倍,非常适合于高亮度激光器和超短脉冲激光器领域的发展应用.
关键词:
2O3陶瓷')" href="#">Yb:Y2O3陶瓷
陶瓷激光器
透明陶瓷 相似文献
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发动机用结构陶瓷研究的发展动向 总被引:3,自引:0,他引:3
先进结构陶瓷在发动机上的应用是国际上陶瓷界和发动机界共同感兴趣的热门研究课题。文章主要介绍了汽车用陶瓷燃气轮机和低散热陶瓷柴油机的研究开发现状、存在问题及今后发展动向。 相似文献
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PZT95/5陶瓷是锆钛比为95:5的锆钛酸铅铁电陶瓷。利用垂直极化的PZT95/5陶瓷,在冲击加载时,陶瓷材料发生铁电/反铁电相变,剩余极化强度消失,释放出被束缚的电荷,电荷流经阻性外电路负载,形成电流输出的性能,可制作恒流型脉冲电源。本文对外电路为短路状态条件下PZT95/5陶瓷冲击放电的电流输出性能进行了研究。 相似文献
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采用掺铌的锆钛锡酸铅(PNZST)反铁电陶瓷作为研究对象,研究了不同的直流电场作用下,等静压力诱导极化态反铁电陶瓷发生去极化过程(同时发生铁电/反铁电相变)的规律.当极化态样品两端电场强度为6 kV/cm时,去极化压力为128.8 MPa;当极化态样品两端电场强度为-6 kV/cm时,去极化压力为74.2 MPa.在与极化电场方向相反的外加电场作用下极化态样品具有较小的去极化压力.讨论了外加直流电场影响极化态反铁电陶瓷去极化压力的内在机理.得到了不同外置电场下的去极化压力,并绘制了该材料的外加直流电场(<
关键词:
去极化
反铁电体
相变 相似文献
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A study aimed at finding a way of scaling-up a small laboratory reactor employing an electric discharge with a dielectric barrier was carried out. The dielectric used was ferroelectric ceramic material of a high permittivity (? above 1000) comparing to glass (? ≈? 3–10), which is generally used. The main component of the ceramics was BaTiO3. The advantage of using this type of ceramics is related to a considerable increase in power density without the need of increasing voltage which supplies the system. The influence of the thickness and surface of ferroelectric electrodes on the macroscopic characteristics of the discharge and efficiency of chemical process was investigated. Ozone synthesis from oxygen was the reaction under consideration. A new structure of the reactor was proposed comprising a series of parallelly spaced thin ceramic plates. High electric permittivity of the ferroelectric ceramics enables such ?sandwich”? structure to be supplied by only two edge ceramic electrodes. 相似文献
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S. N. Kallaev G. G. Gadzhiev I. K. Kamilov A. R. Bilalov Z. M. Omarov S. A. Sadykov 《Bulletin of the Russian Academy of Sciences: Physics》2007,71(5):688-690
The permittivity and thermal expansion of polarized and unpolarized samples of the ferroelectric ceramic PKR-1 have been investigated in the temperature range 300–700 K. Anomalous behavior of the thermal expansion coefficient is found in the range of ferroelectric phase transitions. The results obtained are analyzed taking into account the specific features of the structure of polar ceramics. 相似文献
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Sidney B. Lang Erling Ringgaard 《Applied Physics A: Materials Science & Processing》2012,107(3):631-638
The introduction of porosity into ferroelectric ceramics has been of great interest in recent years. In particular, studies of porous lead-zirconate-titanate ceramic (PZT) have been made. In the research reported, samples of Ferroperm Pz27 with porosities of 20, 25 and 30% were studied. Very complete measurements were made of all of the physical properties relevant for ferroelectric applications including thermal conductivity and diffusivity, heat capacity, dielectric, pyroelectric, piezoelectric and elastic properties. Scanning electron micrographs indicated a change from 3-0 to 3-3 connectivity with increasing porosity. Although most of the physical properties are degraded by the presence of porosity, both piezoelectric and pyroelectric figures-of-merit are improved because of the markedly reduced relative permittivity. Porous ferroelectric ceramics are very promising materials for a number of applications. 相似文献
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通过添加造孔剂的方法制备了四种不同孔隙率未极化PZT95/5铁电陶瓷. 采用非接触式的数字散斑相关性分析(digital image correltation, DIC)全场应变光学测量技术, 对多孔未极化PZT95/5 铁电陶瓷开展了单轴压缩实验研究, 讨论了孔隙率对未极化PZT95/5铁电陶瓷的力学响应与畴变、相变行为的影响. 多孔未极化PZT95/5铁电陶瓷的单轴压缩应力-应变关系呈现出类似于泡沫或蜂窝材料的三阶段变形特征, 其变形机理主要归因于畴变和相变的共同作用, 与微孔洞塌缩过程无关. 多孔未极化PZT95/5铁电陶瓷的弹性模量、压缩强度都随着孔隙率的增加而明显降低, 而孔隙率对断裂应变的影响较小. 预制的微孔洞没有改善未极化PZT95/5铁电陶瓷材料的韧性, 这是因为单轴压缩下未极化PZT95/5铁电陶瓷的断裂机理是轴向劈裂破坏, 微孔洞对劈裂裂纹传播没有起到阻碍和分叉作用. 准静态单轴压缩下多孔未极化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呈线性衰减, 但相变开始的临界体积应变却不依赖孔隙率. 相似文献
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The effective dielectric, piezoelectric, and elastic constants of two-phase macroscopically piezoactive 3-0 and 3-3 composites
are calculated. It is assumed that one of the components is a polarized ferroelectric ceramic material and the other is an
inactive material with variable elastic properties. The limiting case when the elastic compliances of the inactive material
tend to infinity (porous ferroelectric ceramics) is considered. The adequacy of this model to production technologies of piezoelectric
composites is discussed. Computational results are compared with experimental data. 相似文献
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A. V. Pavlenko S. I. Shevtsova A. T. Kozakov L. A. Shilkina A. A. Pavelko L. A. Reznickenko 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(7):782-785
Ceramic samples of lead ferroniobate (PFN) having a rhombohedral symmetry at room temperature are obtained. Their ferroelectric and magnetic properties in the vicinity of the antiferromagnetic and ferroelectric phase transition temperatures are investigated. The electrophysical parameters of the polarized ceramic are presented. By means of electron-probe microanalysis, the number of inclusions of Fe-containing impurity phases (??0.2 vol %) is revealed to be several times higher than that in grains of the PFN ceramics. It is suggested that the above could be caused by the magnetic properties of PFN at room temperature. 相似文献
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This paper reports on the experimental results of measuring the time elapsed between the loading and the fracture of ferroelectric ceramic specimens under the action of a static electric field and mechanical stresses that differ in magnitude. The dependence of the durability of the specimens on the applied stress is determined for electric fields in the range from 0 to 5 MV/m. It is shown that, in the time range 1–103 s, the durability of the ferroelectric ceramic material substantially increases in weak electric fields (the hardening effect) and significantly decreases in strong electric fields. The results obtained can be explained in terms of the fact that the load and the electric field affect the same defects (fracture nuclei) in the ferroelectric ceramics. 相似文献
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测量了使用溶胶-凝胶工艺制备的(Bi0.5Na0.5)1-xBaxTiO3(x=0.00,0.04,0.06,0.08,0.12)系陶瓷的介电、压电、铁电和热释电性能.由于使用了溶胶-凝胶工艺制备的粉料,因此所有样品的压电性能都得到了较大提高.其中(Bi0.5Na0.5)0.94Ba0.06TiO.3系陶瓷具有该系列最大的压电常数,d33=173×10-12C/N,与传统工艺相比,d33提高了近40%.同时,在一定范围内,随Ba含量的增加,材料的剩余极化Pr和矫顽场Ec逐渐减小,退极化温度逐渐降低.对于(Bi0.5Na0.5)0.94Ba0.06TiO.3系陶瓷,剩余极化和矫顽场分别为25μC/cm2和28kV/cm,退极化温度约为80℃.
关键词:
溶胶-凝胶
压电常数
剩余极化
矫顽场 相似文献