摘 要

氧化锌作为一种多功能半导体介电材料，具有优异的微波吸收性能，能将入射微波通过介电损耗机制，转化成热能。利用ZnO的吸波特性，将吸波发热ZnO陶瓷粉体制备成ZnO泡沫陶瓷，所制得的ZnO泡沫陶瓷，具有三维贯通的孔隙结构，在微波场中，能迅速吸收微波而发热，可以用于制备新型高温热分解装置。本文对ZnO陶瓷烧结条件和ZnO泡沫陶瓷的制备工艺条件进行了研究，就各类因素对ZnO陶瓷性能的影响进行了系统的探究。

研究了不同烧结助剂对ZnO陶瓷性能的作用机理和影响规律。本实验选取了五组掺杂体系：A.Bi₂O₃-ZnO,B.MnO₂-ZnO,C.Na₂SiO₃-ZnO,D.Na₂B₄O₇-ZnO,E.Na₂SiO₃-Na₂B₄O₇-ZnO，在1100℃下常压烧结成ZnO陶瓷，通过发热速度、烧成收缩、XRD、SEM等测试手段，分析了烧结助剂的种类和含量对ZnO陶瓷吸波发热速度、致密度的影响。研究表明：在同种烧结工艺条件下，Na₂SiO₃-Na₂B₄O₇-ZnO试样（水玻璃：硼砂=1:1，质量比）吸波发热时间为13.52s，线收缩率为2.12%，为本实验得出的最佳烧结体系。

研究了ZnO泡沫陶瓷浆料的性能。本实验采用有机泡沫浸渍法制备ZnO泡沫陶瓷，通过ZETA电位、沉降时间、黏度等测试方法探究了PH值、固含量和分散剂用量对浆料性能的影响，研究发现：当固含量为60%，分散剂添加量为0.5%，浆料PH控制为12左右时所得的浆料流动性、黏度等适宜，能很好的涂覆于有机泡沫体表面，无露筋、泡沫体变形现象，且烧结所得ZnO泡沫陶瓷强度较高，抗热震性好。

关键词：ZnO泡沫陶瓷、吸波发热、烧结助剂、浆料性能

Abstract

As a multifunctional semiconductor dielectric material, ZnO has excellent microwave absorption properties and can convert incident microwaves into thermal energy through a dielectric loss mechanism.The ZnO foam ceramics are prepared by absorbing the wave-absorbing ZnO ceramic powders. The obtained ZnO foam ceramics have a three-dimensional through pore structure, and can rapidly absorb microwaves and generate heat in a microwave field. It can used for the preparation of new high-temperature thermal decomposition devices. In this paper, the sintering conditions of ZnO ceramics and the preparation conditions of ZnO foam ceramics are studied, and the influence of various factors on the performance of ZnO ceramics is systematically explored.

The mechanism and effect of different sintering aids on the properties of ZnO ceramics were studied.In this experiment,five groups of doping systems were selected: A.Bi₂O₃-ZnO. B.MnO₂-ZnO.C.Na₂SiO₃-ZnO.D.Na₂B₄O₇-ZnO.E.Na₂SiO₃-Na₂B₄O₇-ZnO.ZnO ceramics was sintered at 1100℃ under normal pressure, the effect of the type and content of sintering additives on the wave-absorbing heating rate and density of ZnO ceramics was analyzed by means of heat generation rate, sintering shrinkage, XRD and SEM. The results show that under the same sintering conditions, the Na₂SiO₃-Na₂B₄O₇-ZnO sample (water glass: borax = 1:1, mass ratio) absorbs wave heating time is 13.52s, the linear shrinkage rate is 2.12%, the best sintering system based on the experimental results.

The properties of ZnO foam ceramic pastes were investigated. In this experiment, ZnO foam ceramics were prepared by organic foam impregnation method. The influences of pH value, solid content and dispersant dosage on the performance of slurry were explored through ZETA potential, sedimentation time, viscosity and other test methods. The study found that: when the solid content is 60% ,the amount of dispersant added is 0.5%.,the pH of the slurry is controlled to about 12, the obtained slurry has suitable flowability, viscosity, etc., and can be well applied to the surface of the organic foam without the phenomenon of deformation of the exposed foam or foam, and The sintered ZnO foam ceramics have high strength and good thermal shock resistance.

Keywords:ZnO foam ceramics, wave absorbing heat, sintering aids, slurry propertie

目录

摘 要 I

Abstract II

第1章 绪论 1

1.1 ZnO的结构特点和吸波性能 1

1.1.1 ZnO的晶体结构 1

1.1.2 ZnO吸波性能的研究现状 1

1.2 ZnO泡沫陶瓷的制备方法 2

1.2.1 有机泡沫浸渍法 2

1.2.2 发泡法 2

1.2.3 凝胶注模法 3

1.2.4 添加造孔剂法 3

1.3本设计的研究目的和内容 3

第2章 实验 4

2.1实验原料、仪器和设备 4

2.2 实验工艺过程 5

2.2.1 ZnO陶瓷的制备 5

2.2.1.1 成分设计 6

2.2.1.2 配料 6

2.2.1.3 混料 7

2.2.1.4 干压成型 7

2.2.1.5 烧结 8

2.2.2 ZnO泡沫陶瓷的制备 8

2.2.2.1 前驱体的预处理 8

2.2.2.2 烧成 9

2.3 性能表征方法 9

第3章 结果与分析 11

3.1 烧结助剂对ZnO陶瓷的影响 11

3.1.1 单一烧结助剂对致密度的影响 11

3.1.2 单一烧结助剂对发热速率的影响 14

3.1.3 复合烧结助剂研究 15

3.1.4 不同烧结助剂的作用机理分析 17

3.1.4.1 掺Mn氧化锌陶瓷作用机理 17

3.1.4.2 掺硼硅玻璃的氧化锌陶瓷作用机理 18

3.2 制备工艺对ZnO泡沫陶瓷的影响 20

3.2.1 ZnO浆料Zeta电位与PH关系 20

3.2.2 固含量对沉降时间的影响 21

3.2.3 分散剂用量对分散效果的影响 22

第4章 结论与展望 25

4.1 结论 25

4.2 展望 25

参考文献 26

致 谢 28

第1章 绪论

1.1 ZnO的结构特点和吸波性能

1.1.1 ZnO的晶体结构

在常温下，氧化锌的禁带宽度为3.37ev，具有压电和光电特性，是一种优良的宽禁带半导体材料，ZnO具有三种不同的晶体结构：纤锌矿型结构、闪锌矿型结构、四方岩盐矿结构^[1]。室温时，ZnO的结晶态为纤锌矿型结构。纤锌矿点群为6mm，空间群为P6₃mc，属于六方晶系，晶胞结构如图1-1所示：