發(fā)布時間：2018-10-22 18:20

【摘要】：傳統(tǒng)壓電陶瓷的壓電性在溫度高于居里點時會消失,這極大的限制了壓電陶瓷在高溫下的應(yīng)用。利用鐵電材料的撓曲電效應(yīng)設(shè)計撓曲電壓電材料能解決這一問題。本文主要通過實驗提出兩種設(shè)計撓曲電壓電材料的方法,當(dāng)鐵電陶瓷圓片放置在金屬環(huán)或通過不同組分的陶瓷在高溫擴散使其具有拱形結(jié)構(gòu),在應(yīng)力的作用下都可以得到由撓曲電效應(yīng)產(chǎn)生的表觀壓電響應(yīng),并且表觀壓電響應(yīng)可以在溫度高于居里點時仍穩(wěn)定存在。本論文提供了一種方法可以設(shè)計出在高溫機電應(yīng)用的材料。(1)提出點環(huán)設(shè)計即把壓電陶瓷片放在金屬圓環(huán)上,通過在樣品中心點施加壓力,使樣品彎曲產(chǎn)生撓曲電效應(yīng)得到表觀壓電響應(yīng)。簡單的公式推導(dǎo)可以證明由撓曲電效應(yīng)可以產(chǎn)生表觀壓電響應(yīng)。利用點環(huán)設(shè)計得到BaTi03壓電陶瓷表觀壓電系數(shù)d33達(dá)256pC/N,計算得到的撓曲電系數(shù)數(shù)量級其他鐵電氧化物一致。BTO陶瓷圓片的表觀d33可以在高溫(Tc)穩(wěn)定存在,在300℃為167pC/N。(2)為了簡化點環(huán)設(shè)計,提出一種由兩種不同組分的陶瓷圓片在高溫擴散形成的拱形結(jié)構(gòu)(點面設(shè)計),當(dāng)具有拱形結(jié)構(gòu)的陶瓷片在沒有圓環(huán)的支撐時,受到力的作用可以產(chǎn)生彎曲和撓曲電效應(yīng)。NBBT6陶瓷樣品分別與NBBT8陶瓷樣和BST陶瓷進(jìn)行擴散,得到具有拱形結(jié)構(gòu)的NBBT6、NBBT8與BST陶瓷的表觀d33在高溫(Tc)仍存在,在400℃,NBBT6表觀d33為10pC/N,NBBT8陶瓷為7pC/N。居里溫度Tc低于常溫的BST陶瓷圓片的表觀d33直到200℃仍為1pC/N。
[Abstract]:The piezoelectric properties of traditional piezoelectric ceramics will disappear when the temperature is higher than the Curie point, which greatly limits the application of piezoelectric ceramics at high temperature. Using the flexural effect of ferroelectric materials to design flexural voltage-electric materials can solve this problem. In this paper, two methods of designing flexural voltage-electric materials are put forward by experiments. When ferroelectric ceramic wafers are placed in metal rings or diffused at high temperature by different components of ceramics, they have arched structures. Under the action of stress, the apparent piezoelectric response caused by the flexural effect can be obtained, and the apparent piezoelectric response can still exist stably when the temperature is higher than the Curie point. In this paper, a method is provided to design materials for high temperature electromechanical applications. (1) A point ring design is proposed, in which piezoelectric ceramic chips are placed on metal rings and applied pressure at the center of the sample. The surface piezoelectric response was obtained by flexural electric effect of the sample. The simple formula derivation can prove that the apparent piezoelectric response can be generated by the flexural electric effect. The apparent piezoelectric coefficient d33 of BaTi03 piezoelectric ceramics is up to 256 PC / N by point ring design. The calculated flexural electrical coefficient is consistent with that of other ferroelectric oxides. The apparent d33 of BTO ceramic wafer can exist stably at high temperature (Tc). In order to simplify the design of point ring at 300 鈩，

本文編號：2287946