论文总字数：17623字

摘 要

本文简单介绍了微波介质陶瓷的定义，分类以及烧结助剂对微波介质陶瓷性能的影响。本实验以Al₂O₃陶瓷为基础，添加不同种类的烧结助剂，研究烧结助剂对其微波介电性能的影响。实验使用的烧结助剂为MoO₃和CaMoO₄，通过对比两种烧结助剂对陶瓷介电性能的影响，确定比较合适的烧结助剂及其百分含量。此外，还研究了烧成温度对Al₂O₃微波介质陶瓷性能的影响，以此确定最佳的温度点。本实验采用阿基米德法测试其气孔率和体积密度，用XRD衍射分析仪分析样品的晶相组成，最后测试其介电性能并分析数据。实验需达到的性能要求：介电常数为9左右；谐振频率温度系数近零时，品质因数越高越好。

从XRD主要衍射峰得出结论：Al₂O₃陶瓷以α-Al₂O₃为主晶相。随着烧结温度的变化，在加入不同种类，不同含量的烧结助剂后介电常数变化趋势也有所不同，Q×f值也有所改变。对比试验结果，最终确定：选用2%MoO₃烧结助剂加入Al₂O₃陶瓷，最佳烧结温度1600℃，最佳介电性能：介电常数ε_r=11.32，品质因数Q×f=19804GHz。

关键词：微波介质陶瓷，Al₂O₃，陶瓷烧结助，MoO₃

Effects of Additives on Properties of Alumina-Based Microwave Dielectric Ceramics Abstract

Abstract

In this paper, the definition and classification of microwave dielectric ceramics and the influence of sintering aids on the properties of microwave dielectric ceramics are briefly introduced. In this experiment, based on Al2O3 ceramics, different kinds of sintering aids were added to study the influence of sintering aids on microwave dielectric properties. The sintering aids used in this experiment are MoO₃ and CaMoO₄. By comparing the effects of the two sintering aids on the dielectric properties of the ceramic, a suitable sintering aid and its percentage content are determined. In addition, the effect of firing temperature on the performance of Al₂O₃ microwave dielectric ceramics was also studied to determine the best temperature point. In this experiment, the Archimedes method was used to test the porosity and bulk density, and the crystal phase composition of the sample was analyzed using an XRD diffraction analyzer. Finally, the dielectric properties of the sample were tested and the data analyzed. The performance required for the experiment: dielectric constant is about 9; when the resonant frequency temperature coefficient is near zero, the higher the quality factor, the better.

From the main XRD diffraction peaks, it is concluded that the Al₂O₃ ceramics are mainly α-Al₂O₃. With the change of sintering temperature, the dielectric constant changes after adding different kinds of sintering aids, and the Q×f value also changes. Comparison of test results, the final determination: the choice of 2% MoO₃ sintering additives Al₂O₃ ceramics, the best sintering temperature of 1600℃, the best dielectric properties: dielectric constant ε_r = 11.32, quality factor Q × f = 19804GHz.

Key Words:Microwave Dielectric Ceramics; Al₂O₃; Sintering additives; MoO₃

目录

摘要 I

ABSTRACT II

第一章引言 1

1.1 微波介质陶瓷的研究现状 1

1.1.1微波介质陶瓷的概念 1

1.1.2氧化铝基微波介质陶瓷 1

1.1.3微波介质陶瓷体系 2

1.2微波介质陶瓷性能测试方法 3

1.2.1介电常数 3

1.2.2损耗 4

1.2.3频率温度系数 4

1.3其他低介电常数微波介质陶瓷 4

1.3.1稀土铝酸盐系列 4

1.3.2MgSiO₄橄榄石陶瓷 5

1.3.3ABO₃型钙钛矿系列 5

1.4烧结助剂 6

1.4.1烧结助剂的意义 6

1.4.2复合烧结助剂 6

1.5本论文研究的主要内容 7

第二章实验研究方法 8

2.1实验原料与设备 8

2.1.1原料与试剂 8

2.1.2仪器与设备 8

2.2实验流程 9

2.3结构与性能表征 10

2.3.1密度的测定 10

2.3.2X射线衍射分析 11

2.3.3介电性能测试 11

第三章结果与讨论 12

3.1引言 12

3.2实验方法 12

3.3数据与分析 13

3.3.1烧结性能分析 13

3.3.2介电性能分析 17

3.3.3相组成测试分析 22

第四章结论与展望 22

1.1结论 22

1.2展望 23

参考文献 23

致谢 26

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