PZT（压电陶瓷）在声呐中表现出的性质是物理性质还是化学性质

1、伸缩量与条纹移动级数成比例
2、在不同频率下的驱动电压取决于驱动电路的频率特性,如果频率刚好是压电陶瓷的共振频率那么振幅最大,为一个极值.

The piezoelectricity ceramics have quickly respond, the energy densityhigher characteristic, in domain and so on precision machinery,speaker, absorption of shock noise reduction obtained the widespreadapplication, in the intelligent structure, its function may notsubstitute in particular. But the traditional pressure ceramicsactually have the obvious insufficiency, because actuation strain toosmall, is very difficult to satisfy the actual project application theneed. In order to obtain the bigger actuation strain, the peoplestudied the many kinds of piezoelectricities actuation part, likedouble curved piezoelectricity driver, " Mooine" Brass -PZTcombination driver, kind of alone stone structure actuation part andso on. But these all belong to the machinery to enlarge the mechanismthe application, while obtains a bigger strain, also reduced thedriving influence, from essentially solves the problem by no means.
The piezoelectricity ceramics application is extremely widespread, themost typical application is the buzzer and the security alarmapparatus, after 素坯 rolls over the ceramics the image formationpaper same thin slice to fire, makes the electrode in its both sides,then the polarization, such ceramics had the piezoelectricity, then itwith the tinsel agglutinated again in together, made a buzzer. Whenelectrode circular telegram, the piezoelectricity ceramics because thecounter piezoelectric effect has the vibration, makes sound which theperson ear may hear. Through the electronic circuit control, may havethe different frequency vibration, thus makes the different sound, thebuzzer most early uses on the electronic toy, now also uses in thefire engine, the ambulance, the safe cabinet and so on place takes thealarm apparatus. Can transform using the piezoelectricity ceramics themechanical energy the electrical energy the characteristic, but alsomay make " Ceramic ear " . In front of the common earthquakebecause the earth's crust interior unusual games sends out 地声, theceramic ear may the sound which hears turn the electrical signal inputcomputer, like this may 地声 forecast the earthquake through themonitor.
The sound motor is in the piezoelectricity ceramics application anoticeable new domain. It is uses the piezoelectricity ceramics thecounter piezoelectric effect, directly transforms the electricalenergy the mechanical energy output not to need the magnet coil thenew electrical machinery, compares with the ordinary electromagnetismmotor, it has the structure simply, starts, the volume quickly young,the power loss is low and so on the characteristic. Moreover, becauseit is directly transforms from the electrical energy into themechanical energy but does not transform through themagnetoelectricity, therefore, does not have the magnetism disturbancenot to fear the magnetism disturbance. It also may the low speedmovement but not use the reduction gear. This kind of miniatureelectrical machinery in the aviation, astronautics, the precisionmachinery, the instrument measuring appliance, the automatic control,the robot, the scanning electricity mirror moves slightly, thephotographic camera automatic focusing, the magnetic head moves, themotor vehicle windshield wiper and the electrically operated switchglass and so on many areas of technology has the broad applicationprospect.
The former piezoelectricity ceramics were by several microns thepolytropism material which was composed to several dozens micronsmulti- domains crystal grains, the size have not been able to meetthe needs. Reduces the particle size to an Asian micron level, mayimprove the material the workability, may do the substrate is thinner,may enhance the array frequency, reduces the transducer array theloss, enhances the component the mechanical strength, reducesmultilayered component each level thickness, thus reduces the slavingvoltage, this to enhances folds the level transformer, the brake allis beneficial. Reduces the particle size to have the above so manyadvantage, but simultaneously also brought reduced the piezoelectriceffect the influence. In order to overcome this kind of influence, thepeople changed the traditional doping craft, makes 细晶粒 thepiezoelectricity ceramics piezoelectric effect to increase to and粗晶粒 the piezoelectricity ceramics suitable level. Nowmanufactured 细晶粒 the material cost to be possible to competewith the ordinary ceramics. In recent years, the people carried onwith 细晶粒 the piezoelectricity ceramics have cut grind theresearch, and manufactured some high frequency transducers, the microbrake and the thin buzzer (porcelain piece 20-30um is thick), hasproven 细晶粒 the piezoelectricity ceramics superiority. Along withthe nanotechnology development, 细晶粒 the piezoelectricity ceramicmaterial research and the application development was still theshort-term hot spot. Moreover, the piezoelectricity body is the launchand the receive ultrasonic wave ideal material. When the alternationelectrical signal function to the piezoelectricity body, has thedeformation because of the counter piezoelectric effect, gets off anaircraft 电耦合 the resonance in the suitable frequency to launchthe ultrasonic wave, thus the constitution launch pokes head in, butwhen the ultrasonic wave does uses in the piezoelectricity body, as aresult of the undulation mechanical power function, can because of thepiezoelectric effect but in the piezoelectricity body correspondingsurface produce the electrical signal to output, the constitutionreceive pokes head in. Pokes head in with this kind to be allowed tomanufacture the ultrasonic flaw detector survey object interior theflaw, but also may make the supersonic microscope, the supersonicthickness gauge and so on.

水晶晶体在不受力时,其正电荷中心与负电荷中心重合,整个晶体的总电矩为零,晶体表面不带电.当晶体受力时,由于形变而导致正负电荷中心不再重合,晶体两端表面就带电了,这种正负电荷中心不重合的现象叫做极化.也有少数压电晶体由于本身内部的特殊结构,在没有外电场的情况下就存在着极化现象,这样的极化为自发极化.这种具有自发极化的晶体中存在一些自发极化取向一致的微小区域,称为电畴.当其被放入电场中后,原来随机混乱取向的电畴就会沿电场方向取向,若电场再反向,自发极化单元也会跟着反向,称之为电滞回线 ,与铁磁体的磁滞回线形状类似,所以人们把这类晶体称为铁电体(其实晶体中并不含有铁),这个回线就是铁电体的标志.显然 ,铁电体是压电体中的一种.
所以铁电陶瓷是压电陶瓷的一种.

原理上压电陶瓷是将震动的机械能转化为电能,但是在转化过程中压电陶瓷存在阻尼效应,电能必须能够及时存储和利用.希望把分给我.嘿嘿!

C

根据燃烧需要同时满足三个条件：①可燃物 ②氧气或空气 ③达到燃烧所需的最低温度即着火点，可知要使打火机燃烧必须具备：电火花，氧气即通风口，可燃物．故选C．

PZT4,是压电陶瓷材料的一种.肯定有压电效应的.
有压电效应的陶瓷片,受到压力都会产生电压.

你应该是问d33吧,一般极化过的压电陶瓷都是去测d33,好一点的含铅的陶瓷应该是四五百,最高七八百 pC/N,一般无铅的做到一二百就很了不起了.表征压电d33有两个单位pC/N和pm/V,其实是等价的,陶瓷一般用pC/N

如果是倒车雷达用的,应该是很小体积的,比如10*0.2的.如果是工业用的,测距可以在10m左右的.应该用直径50,厚度10mm的.如果是纵向振子的,可以用38*15*5的.

Piezoelectric ceramics,a can of mechanical energy and electrical energy conversion function with each other ceramic materials.In energy conversion,the use of piezoelectric ceramics to mechanical energy into electrical energy conversion features,you can create a piezoelectric igniter,mobile X-ray power supply,such as artillery shells detonated device.Piezoelectric ceramic with sensitive characteristics,can be an extremely weak electrical signals into mechanical vibration,can be used for sonar systems,weather detection,remote sensing of environmental protection,and household appliances.Converter voice:the voice of converter is one of the most common applications.Like a pickup,microphone,headphones,buzzer,ultrasonic detection of deep-yee,sonar,ultrasonic flaw detector materials can all be done with voice piezoceramic converters.Such as children's toys on the Ming-feng is the current through the device of the piezoelectric ceramic piezoelectric vibration effect,and the issue of the human ear can hear voices.Piezoelectric ceramic electronic control circuit can have different frequencies of vibration,which issued a variety of different voices.For example,electronic music greeting cards,that is,through the piezoelectric effect to convert the exchange of mechanical vibration signals.Through the voices of the outside world,the vibration sound amplification,the amplification of the vibration applied to the piezoelectric ceramic on ceramic pressure point under pressure to produce electricity .Device and then connect a storage device,will be transformed into energy savings,and then use the time.

压电陶瓷在被压缩变形时,引起其内部正负电荷中心相对位移而发生极化,导致材料两端表面出现符号相反的束缚电荷的现象,因其两表面产生正负电荷而产生电压,称为压电效应.如果两表面通过导体进行放电,瞬间产生电流,至两表面的电位相等时电流即中止.其放电过程类似于电容的放电过程,是瞬间的,时间长短决定于产生的电压高低、电荷的多少和放电电路的阻抗大小.

打火机的压电陶瓷在瞬间大约能产生60V的电压,即使能产生这么高的电压,但是打火机的压电陶瓷的传引太细,不能够产生大的火星,因此理论上来说仍然点燃不了黑火药!给分吧!

解题思路：根据压电陶瓷也是陶瓷中的一种，属于无机非金属材料进行解答．

压电陶瓷也是陶瓷中的一种，属于无机非金属材料，而不是金属材料、有机合成材料、超导材料．
故选：C．

点评：
本题考点： 新材料的开发与社会发展的密切关系．

考点点评： 本题利用生活中某一实例，考查了材料的应用，揭示了化学来源于生活又应用于生活的化学意识．

解题思路：根据图象，结合题意，得到压力的变化规律，再根据牛顿第二定律判断出加速度的变化规律，从而得到小车的运动情况．

A、B、从t₁到t₂时间内，压电陶瓷两端电压变大，故受到的压力变大，故其对小球有向右且不断变大的压力，故小球的加速度不断变大，水平向右，由于速度向右，故小球向右做加速度不断变大的加速运动，故A正确，B错误；
C、D、从t₂到t₃时间内，电陶瓷两端电压不变，故受到的压力恒定，故其对小球有向右且恒定大的压力，故小球的加速度恒定，水平向右，由于速度向右，故小球向右做匀加速直线运动，故C正确，D错误；
故选AC．

点评：
本题考点： 牛顿第二定律；闭合电路的欧姆定律．

考点点评： 本题关键是对小球受力分析，根据图象得到压力的变化规律，然后根据牛顿第二定律判断出加速度的情况，最后得到小车的运动情况．

压电陶瓷具有敏感的特性,可以将极其微弱的机械振动转换成电信号,可用于声纳系统、气象探测、遥测环境保护、家用电器等.地震是毁灭性的灾害,而且震源始于地壳深处,以前很难预测,使人类陷入了无计可施的尴尬境地.压电陶瓷对外力的敏感使它甚至可以感应到十几米外飞虫拍打翅膀对空气的扰动,用它来制作压电地震仪,能精确地测出地震强度,指示出地震的方位和距离.这不能不说是压电陶瓷的一大奇功.压电陶瓷在电场作用下产生的形变量很小,最多不超过本身尺寸的千万分之一,别小看这微小的变化,基于这个原理制做的精确控制机构－－压电驱动器,对于精密仪器和机械的控制、微电子技术、生物工程等领域都是一大福音.谐振器、滤波器等频率控制装置,是决定通信设备性能的关键器件,压电陶瓷在这方面具有明显的优越性.它频率稳定性好,精度高及适用频率范围宽,而且体积小、不吸潮、寿命长,特别是在多路通信设备中能提高抗干扰性,使以往的电磁设备无法望其项背而面临着被替代的命运.

解题思路：根据燃烧的条件（燃烧需要同时满足三个条件：①可燃物②氧气或空气③达到燃烧所需的最低温度即着火点）解答本题．

根据燃烧需要同时满足三个条件：①可燃物 ②氧气或空气 ③达到燃烧所需的最低温度即着火点，可知要使打火机燃烧必须具备：电火花，氧气即通风口，可燃物．
故选C．

点评：
本题考点： 燃烧与燃烧的条件．

考点点评： 本题考查学生依据燃烧需要同时满足的三个条件进行分析解题的能力．

压电陶瓷,一种能够将机械能和电能互相转换的功能陶瓷材料,属于无机非金属材料.这是一种具有压电效应的材料.
所以是无机非金属材料.不属于有机物

解题思路：压电效应是大拇指压一下，消耗了机械能，产生10kV～20kV的高压，形成火花放电，即得到了电能．

转化前要消耗机械能，转化后得到了电能，所以为机械能转化为电能．
故选D

点评：
本题考点： 能量的转化．

考点点评： 能量转化要明确转化前是什么能，消耗了什么能，转化后是什么能，得到什么能．

design of measurement experiment on the piezoelectric ceramics electrostrictive coefficient of CCD

能使压电陶瓷震动.
用得最多的是做压电陶瓷的扬声器,比如音乐贺卡、某些小电子钟的音乐报时.
精密机械领域,有使用压电效应做微型电动机的.