论文总字数：28288字

摘 要

本文首先对压电陶瓷的发展过程以及当前社会由于广泛使用含铅压电陶瓷体系产生的后果进行了阐述，然后对三种较主流的无铅压电陶瓷体系——铌酸硅钠基无铅压电陶瓷（简称KNN基陶瓷）、锆钛酸钡基无铅压电陶瓷（简称BZT基陶瓷）、钛酸铋钠基无铅压电陶瓷（简称BNT基陶瓷）的优点与缺点进行了简要的介绍，并对近年关于这些陶瓷体系的研究成果进行了介绍；并主要介绍了较有可能取代含铅压电陶瓷的BNT基陶瓷，从结构的角度解释其压电性能的来源，并从BNT基无铅压电陶瓷的自身性能缺陷分析了其不能投入实用的原因；然后通过介绍近年来国内外在BNT基无铅压电陶瓷上取得的研究成果引出BNT基无铅压电陶瓷实用化难题的可能的解决办法。同时，本文介绍了使用高温固相法制备BNT-ST无铅压电陶瓷的工艺流程，并指出了制备过程中的一些需要注意的操作。

本文对(1-x）Bi_0.5Na_0.5TiO₃-xSrTiO₃（缩写为BNT-100xST）无铅陶瓷性能影响因素进行了探究，主要分为两个部分。一是在不同的温度下烧结相同组成的BNT-25ST无铅压电陶瓷，观察其形貌特征，分析其性能，发现在1190 C下烧结的BNT陶瓷性能最好，在E=40 kV/cm的外加电场下表现出的单极应变S_max为0.23 %，归一化应变d₃₃*的数值为585.00 pm/V；双极应变S_max为0.23 %，归一化应变d₃₃*的数值为570.00 pm/V。三项主要性能P_max、P_r、E_c的数值是39.77 μC/cm²，19.66 μC/cm²，9.40 kV/cm。二是在相同温度下烧结不同组分构成的BNT-100xST陶瓷（x=0.19、0.21、0.23、0.25、0.27），观察其形貌特征，分析其性能，发现SrTiO₃掺杂量为23 mol%时BNT-23ST陶瓷的性能最佳，在E=40kV/cm的外加电场下表现出的单极应变S_max为0.32 %，归一化应变d₃₃*的数值为790.00 pm/V；双极应变S_max为0.33 %，归一化应变d₃₃*的数值为825.00 pm/V。它的三项主要电学性能P_max、P_r、E_c的数值是40.95 μC/cm²，21.29 μC/cm²，9.68 kV/cm。

关键词：无铅压电陶瓷 BNT基陶瓷 SrTiO₃掺杂 应变性能

Preparation and Properties of BNT-ST Lead-Free Piezoelectric Ceramics

Abstract

This article first introduced the development of piezoelectric ceramics and the consequences of the widespread use of lead-containing piezoelectric ceramic systems in the current society. Then, the advantages and the disadvantages of three lead-free piezoelectric ceramic systems----sodium niobate-based lead-free piezoelectric ceramics (abbreviated as KNN-based ceramics), zirconium titanate-based lead-free piezoelectric ceramics (abbreviated as BZT-based ceramics), and sodium barium titanate-based lead-free piezoelectric ceramics (abbreviated as BNT-based ceramics) were briefly described, and introduced the research results of these ceramic systems in recent years. The BNT-based ceramics, which are more likely to replace lead-containing piezoelectric ceramics, were mainly introduced. The sources of piezoelectric performance were explained from the view of crystal structure, and analuzed the reason for reasons why they cannot be put into practical use on own performance defects. Then, by introducing recent research results on BNT-based lead-free piezoelectric ceramics both in domestic and at abroad, possible solutions to the practical problems of BNT-based lead-free piezoelectric ceramics have been introduced. At the same time, this article describes the process flow of preparing BNT-ST lead-free piezoelectric ceramics using high-temperature solid-phase method, and points out some operations that need attention in the preparation process.

In this paper, the influencing factors of (1-x)Bi_0.5Na_0.5TiO₃-xSrTiO₃ (abbreviated as BNT-100xST) lead-free ceramics performance are explored and divided into two parts. One is to sinter the same composition of BNT-25ST lead-free piezoelectric ceramics at different temperatures. Observe its morphology characteristics and analyze its performance. It is found that the BNT-25ST ceramic sintered at 1190 C has the best performance at E=40 kV/cm. The unipolar strain S_max exhibited by the applied electric field is 0.23 %, the normalized strain d₃₃* is 585.00 pm/V, the bipolar strain S_max is 0.23 %, and the normalized strain d₃₃* is 570.00 pm/V. .The values of its three main electrical properties, P_max, P_r, and E_c, were 39.77 μC/cm², 19.66 μC/cm², and 9.40 kV/cm. The second part is to sinter the BNT-100xST ceramics (x=0.19, 0.21, 0.23, 0.25, 0.27) composed of different components at the same temperature. Observe the morphology and analyze their properties, and find that the best doping amount of SrTiO₃ is 23 mol%. The performance of BNT-23ST ceramic is the best. The unipolar strain S_max is 0.32 %, the normalized strain d₃₃* is 790.00 pm/V and the bipolar strain S_max is 0.33 % under the applied electric field of E=40 kV/cm. %, the normalized strain d₃₃* is 825.00 pm/V. The values of its three main electrical properties, P_max, P_r, and E_c, are 40.95 μC/cm², 21.29 μC/cm², and 9.68 kV/cm.

Key word:Lead-free; Piezoelectric ceramics; BNT ceramics; SrTiO₃ doping; Strain performance

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1 引言 1

1.2压电陶瓷发展简介 1

1.3主要无铅压电陶瓷体系简介 2

1.3.1 KNN基无铅压电陶瓷 2

1.3.2 BZT基无铅压电陶瓷 3

1.3.3 BNT基无铅压电陶瓷 4

1.4 本课题研究目的、意义及研究内容 5

1.4.1研究目的和意义 5

1.4.2研究内容 6

第二章 实验方法与性能测试 7

2.1 实验原料及设备 7

2.1.1实验原料 7

2.1.2 实验设备 7

2.2 实验工艺及流程 8

2.3 实验表征方法 10

第三章 BNT-100xST陶瓷的性能研究 11

3.1不同烧结温度制备BNT-25ST陶瓷及性能研究 11

3.2.1实验内容 11

3.2.2 不同烧结温度对BNT-25ST陶瓷物相的影响 11

3.2.3 不同烧结温度对BNT-25ST陶瓷微观形貌的影响 11

3.2.4不同烧结温度对BNT-25ST陶瓷电滞回线的影响 13

3.2.5不同烧结温度对BNT-25ST陶瓷电致应变曲线的影响 14

3.2 ST组分掺入量不同的BNT-100xST陶瓷制备及性能研究 15

3.2.1研究内容 15

3.2.2 ST组分掺入量不同对BNT-100xST陶瓷电滞回线的影响 16

3.2.3 ST组分掺入量不同对BNT-100xST陶瓷电致应变曲线的影响 17

3.3本章小结 17

第四章 结论与展望 20

4.1 结论 20

4.2 展望 20

参考文献 21

致 谢 24

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