PZN-PZT压电陶瓷高温石墨还原行为研究

为研制具有超大位移量的 Ｒ Ａ Ｉ Ｎ Ｂ Ｏ Ｗ 新型压电微位移驱动器, 对制备该器件所用铌锌酸铅 锆钛酸铅（ Ｐ Ｚ Ｎ Ｐ Ｚ Ｔ） 压电陶瓷材料的还原行为进行了初步研究, 观察到还原样品断口上呈现出清晰的多层层次结构采用 Ｓ Ｅ Ｍ、 Ｘ Ｒ Ｄ 和电导率测量等研究方法, 研究了还原样品各层次的断口形貌、物相组成和导电类型, 对 Ｐ Ｚ Ｎ Ｐ Ｚ Ｔ 压电陶瓷材料在高温下被石墨还原的过程和机理作了初步解释研究表明还原反应是按照先晶界后晶粒的顺序进行, 各层的导电类型随还原程度由浅到深呈现出绝缘体型 半导体型 金属型的变化规律, 对于轻度还原层, 仍保持着初始的固溶体晶相结构, 相应地对深度还原层, 初始晶相结构已被破坏, 由分解的复相所构成.     

PZN-PZT压电陶瓷高温石墨还原行为研究

为研制具有超大位移量的 Ｒ Ａ Ｉ Ｎ Ｂ Ｏ Ｗ 新型压电微位移驱动器， 对制备该器件所用铌锌酸铅锆钛酸铅（ Ｐ Ｚ Ｎ Ｐ Ｚ Ｔ） 压电陶瓷材料的还原行为进行了初步研究， 观察到还原样品断口上呈现出清晰的多层层次结构采用 Ｓ Ｅ Ｍ、 Ｘ Ｒ Ｄ 和电导率测量等研究方法， 研究了还原样品各层次的断口形貌、物相组成和导电类型， 对 Ｐ Ｚ Ｎ Ｐ Ｚ Ｔ 压电陶瓷材料在高温下被石墨还原的过程和机理作了初步解释研究表明还原反应是按照先晶界后晶粒的顺序进行， 各层的导电类型随还原程度由浅到深呈现出绝缘体型半导体型金属型的变化规律， 对于轻度还原层， 仍保持着初始的固溶体晶相结构， 相应地对深度还原层， 初始晶相结构已被破坏， 由分解的复相所构成     

双向拉伸聚苯乙烯（BOPS）──美日食品包装的新宠物

双向拉伸聚苯乙烯（ＢＯＰＳ）──美日食品包装的新宠物吴凤展ＢＯＰＳ，ＡＮＥＷＦＡＶＯＵＲＩＴＥＩＮＦＯＯＤＰＡＣＫＡＧＩＮＧＩＮＴＨＥＵ．Ｓ．Ａ．ＡＮＤＪＡＰＡＮ￥ＷｕＦｅｎｇｚｈａｎＡｂｓｔｒａｃｔ：ＢＯＰＳｓｈｅｅｔｉｓｎｏｔｍａｎｕｆａｃｔｕｒ...     

大尺寸新型压电材料四硼酸锂晶体

大尺寸新型压电材料四硼酸锂晶体四硼酸钾（ＬＢＯ）晶体是八十年代发现的一种新型非铁电压电材料，它具有良好的零延迟温度系数（ＴＣＤ—０）和高的ＳＡＷ耦合系数（Ｋ‘），是制作声表面波（ＳＡＷ）和体表面波（ＢＡＷ）器件的温度补偿型基片材料．ＬＢＯ晶体是继水晶...     

应力对压电陶瓷驱动器位移性能的影响

在研制由钨青铜型压电陶瓷分立驱动器组装成特种圆环状压电驱动器中,发现组装后横向位移模圆环驱动器的位移量呈现异常的变化;它的位移量比分立器件的增加可达～３０％．对组成、器件制备等进行了大量实验,分析认为;分立器件在组装后处于严重的压应力中,它对逆压电效应的影响是上述结果的原因．它的主要机制是在压应力下通过９０°畴重新取向或钨青铜结构中基本组元－氧八面体的畸变使自发极化偏离于原压应力方向,一旦施加电场则造成位移量的大大增加．     

高控位精度横向模压电微位移器的研究

介绍了d31横向伸缩模式压电徽位移驱动器的制作过程,应用高稳定的填满钨青铜型压电陶瓷作为该器件制备的基料,利用P-F干涉仪原理测量了电场-位移特性曲线,由此计算了压电常数d31并进行了讨论。该器件具有电控应变(位移)线性度高、滞后量小以及结构简单、制作工艺方便等特点,它在精密光学等技术领域有一定应用价值。     

CONTENTS OF NEW CARBON MATERIALS OF Vol.16

Ｎｏ .1ＲｅｓｅａｒｃｈａｒｔｉｃｌｅｓＳＴＵＤＹＯＮＴＨＥＭＩＣＲＯＷＡＶＥＡＢＳＯＲＢＩＮＧＰＲＯＰＥＲＴＹＯＦＣＯＭＰＯＳＩＴＥＭＡＴＥＲＩＡＬＣＯＮＴＡＩＮＩＮＧＣＡＲＢＯＮＮＡＮＯＴＵＢＥＳ　ＷＩＴＨＮＩＣＯＡＴＩＮＧＳＨＥＮＺｅｎｇ ｍｉｎ　ＺＨＡＯＤｏｎｇ ｌｉｎ(1) :1………………………………………………………………………ＡＮＥＦＦＥＣＴＩＶＥＭＥＴＨＯＤＦＯＲＰＩＴＣＨＣＯＭＰＯＳＩＴＩＯＮＤＥＳＩＧＮＺＨＩＬｉｎ ｊｉｅ　ＳＯＮＧＪｉｎ ｒｅｎ　ＬＩＵＬａｎｇ(1) :5………………………     

高Tc铋层状压电陶瓷结构与性能

综述了铋层状压电陶瓷的结构特点及性能研究．铋层状压电陶瓷的结构由（Ｂｉ_２Ｏ_２）^２＋层和钙钛矿层（Ａ_ｍ－１Ｂ_ｍＯ_３ｍ＋１）^２－按一定规则共生排列而成．此处 Ａ为适合干 １２配位的离子;Ｂ为适合于八面体配位的离子,ｍ为一整数,其值一般为１～５．与钛酸钡（ＢａＴｉＯ_３）或锆钛酸铅（ＰＺＴ）陶瓷相比,铋层状压电陶瓷具有以下特点：低介电常数、高Ｔ_ｃ、机电耦合系数各向异性明显、低老化率、高电阻率等． 先前研究证明,居里温度不仅与极化原子位移、自发极化强度、Ａ位Ｂｉ含量有关,而且还与取代离子的特性诸如离子半径、电负性、核外电子排布有关．压电活性低是铋层状陶瓷的本质缺点,通常发展该材料的途径为化学取代或晶粒取向技术．研究材料结构与性能之间的关系有助于发展铋层状压电陶瓷材料．     

一种新的不确定推理模型

ＰＲＯＳＰＥＣＴＯＲ的主观ＢＡＹＥＳ方法要求给推理网络中的结点赋先验概率，它在应用和研究中受到限制。本文建立了一个不要求赋先验概率的模型，它能兼容ＭＹＣＩＮ型规则强度和ＰＲＯＳＰＥＣＴＯＲ型规则强度。     

具有大驱动位移的复合结构型PZT压电陶瓷

采用PZT作为基体材料,通过化学还原的方法制备了具有大位移驱动能力的复合结构型压电陶瓷。研究了其预制应力的分布,探索了还原制备工艺,测试了驱动性能。结果表明,复合结构的优化设计方案是,还原层厚度比率为0.3;与普通压电陶瓷驱动器相比,复合结构型PZT压电陶瓷具有较低的谐振频率,驱动位移量提高3倍多;还原层相结构中存在二次氧化的基体相,表明其还原工艺仍需改进。      

基于铁电陶瓷的RAINBOW元件的力学优化设计

基于铁电陶瓷的RAINBOW元件是一种具有内部应力偏移,含有还原层,并有特殊结构的大位移铁电驱动器.本文通过力学方法分析了其应力分布状态,并建立了相应的有限元模型.结果表明,两种分析方法得到了相同的规律,即还原层厚度比率为1/3时元件内部的应力状态最优,有利于获得最大的电场诱导位移.     

Finite element analysis of a deformable array transducer

Deformable array transducers have previously been described to implement 2-D phase aberration correction of near-field aberrators with only a 1xN or 2xN array configuration. This transducer design combines mechanical phase correction using an actuator with electronic phase correction for a 2-D correction with significantly fewer elements than a full 2-D array. We have previously reported the fabrication and results of a 1x32 deformable array fabricated with a RAINBOW (Reduced And INternally Biased Wafer) actuator. Because of the complicated construction of deformable arrays, we propose to use finite element analysis (FEA) as a design tool for array development. In this paper, we use 2-D and 3-D FEA to model the experimental results of the deformable array as the first step toward development of a design tool. Because the deformable array combines a mechanical actuator with a medical ultrasound transducer, improvement in performance must consider both the ultrasound characterization along with the low frequency actuator characterization. For the ultrasound characterization, time domain FEA simulations of electrical vector impedance accurately predicted the measurements of single array elements. Additionally, simulations of pulse-echo sensitivity and bandwidth were also well matched to measurements. For the low frequency actuator characterization, time domain simulation of the low frequency vector impedance accurately predicted measurement and confirmed the fundamental flexure resonance of the cantilever configuration at 1.3 kHz. Frequency domain FEA included thermal processing effects and predicted actuator curvature arising during fabrication. Finally, frequency domain FEA simulations of voltage-induced displacement accurately predicted measured displacement.     

Correlation of the coercive field and reduced layer thickness in piezoelectric RAINBOW ceramics

RAINBOWs are a relatively new type of high-displacement, piezoelectric actuator produced by selectively removing oxygen from one side of a lead-containing ceramic using a high-temperature chemical reduction process. This process yields devices which contain a piezoelectric layer and a metallic layer (i.e., the reduced layer). In this study, piezoelectric RAINBOW actuators with reduced layer-to-total-thickness ratios ranging from 0.05 to 0.8 were produced from five soft-piezoelectric formulations. The ferroelectric hysteresis properties of each specimen were then measured while taking the total thickness of the device to be ferroelectric. Because of this assumption and the metallic nature of the reduced layer, the resulting coercive field measurements were found to correlate strongly with the thickness of the piezoelectric portion of each device. A simple, non-destructive method for estimating the reduced layer thickness in RAINBOW ceramics was devised based on this relationship.     

具有大位移驱动能力的RAINBOW压电陶瓷研究进展

RAINBOW(Reduced And Internally Biased Oxide Wafer)压电陶瓷具有内部应力偏移,兼有还原层和未还原化层,并有特殊的拱形结构.在电场作用下,可以产生很高的轴向位移,能承受比一般压电陶瓷更大的应力载荷,是一种具有广阔应用前景的驱动材料.本文综述了RAINBOW压电陶瓷的力学分析方法、还原机制、微观组织结构、驱动特性,并指出了RAINBOW压电陶瓷的发展趋势.     

晶体结构对压电陶瓷微位移驱动器特性的影响

对钙钛矿结构的ＰＺＴ－５和钨青铜结构的ＰＢＮＮ二种压电陶瓷制成的压电微位移器进行了电压－位移特性的比较和分析，发现我们所研制的ＰＢＮＮ压电微位移器具有线性好、回零好、等优点。     

Deflection characteristics of a trapezoidal multilayer in-plane bending piezoelectric actuator

A novel multilayer split-morph actuator has been designed and fabricated using the thick film screen-printing technology. Deflection characteristics of the split-morph actuator have been investigated by theoretical analysis and experimental measurement. The results indicate that the tip displacement is inversely proportional to the thickness of each piezoelectric layer, but is independent of the number of layers and the total thickness of the actuator. The displacement/voltage sensitivity of the trapezoidal actuator is larger than that of the rectangular design, assuming both have the same width of clamped end and the same thickness of the piezoelectric layers. The maximum displacement/voltage sensitivity of 0.157 micron/V was obtained with a split-morph actuator with 30-micron thick layers. The proposed actuator is a promising candidate for the secondary fine-tuning actuator of a dual stage head-positioning servo system in high density hard disk drives.     

金属成形加工机械执行机构的仿真与动力学分析

目的应用图解法对金属成形加工机械执行机构进行设计,并基于ADAMS和Pro/E软件对机构进行建模仿真及分析。方法根据测量出各铰链受力情况选取典型构件作为柔性构件,在ADAMS柔性模块中对相应刚性构件进行柔性替换,并比较冲头的位移、速度、加速度、曲柄力矩等曲线。结果当机构高速运转时,原动件速度为360(°)/s,柔性构件对冲头的位移、速度、加速度都造成了影响,其中对位移曲线影响不大,对速度、加速度曲线影响明显,对机构的稳定性造成了一定影响。结论当设计高速机构时,必须考虑构件的柔性因素对机构运动特性的影响。     

Novel high-response electromagnetic actuator for electronic engraving system

We describe a new moving-iron electromagnetic actuator that utilizes cantilever-beam-type springs, /spl pi/ type armature, full-bridge magnetic circuits, and a single driving coil. The actuator is suitable for electromechanical converters with high response and minor displacement for use in electronic engraving systems. We analyzed its static and dynamic characteristics by using a three-dimensional finite-element method. We used a simple and practical measuring method based on light reflection to detect the actuator's real hysteresis loop and amplitude frequency response characteristics. The results show that the actuator has a displacement of /spl plusmn/65 /spl mu/m, hysteresis of less than 5.5%, and amplitude cutoff frequency of 3.1 kHz. We tested the actuator on a real engraving system and confirmed its characteristics by the engraving results.     

振动主动控制中电磁作动器动态特性的研究

分析了电磁作动器的动态特性及其对振动主动控制系统振动传递率的影响。振动传递率不仅受作动器动态特性的影响,而且还与反馈变量的选取有关。因此,在实际控制系统中应选择绝对位移、速度、加速度及加加速、绝对位移的积分和相对位移、速度、加速度及加加速度、相对位移的积分的不同组合作为反馈变量,以期取得良好的隔振效果。     

新型形状记忆合金驱动器与三指灵巧手设计

针对现有形状记忆合金（shape memory alloy,SMA）温度反馈控制难以实现及SMA应变量小导致实际应用中存在驱动位移小的问题,提出了一种基于电阻反馈控制的新型SMA驱动器,并采用这种驱动器研发了一种绳索传动的三指灵巧手。新型SMA驱动器由滑轮、空心螺柱、SMA丝和弹簧拉伸装置等组成,通过采用滑轮绕线的方式增长SMA丝的使用长度以提高驱动位移输出量;利用SMA自身的电阻特性得到SMA电阻变化与相变的关系,设计了基于电阻反馈的开关控制系统;采用模块化思想设计了三指灵巧手,3根手指共有8个自由度,并通过实验验证三指灵巧手对物品的抓取能力。结果表明：新型SMA驱动器不需要通过测温来判断SMA丝相变进程,省去了外部温度传感器;SMA驱动器输出的驱动量可达驱动器总长的8%以上;通过监测SMA丝的电阻变化可实现驱动器通电加热的控制,防止SMA丝过热烧毁。研究结果为提高SMA驱动器驱动位移和降低SMA驱动器控制难度提供了一种思路。