摘 要

多孔陶瓷是一种经高温烧成，内部富含气孔结构新型的陶瓷材料。而泡沫陶瓷就是一种宏孔陶瓷，它是普通多孔陶瓷、蜂窝多孔陶瓷之后发展起来的一种具有三维联通孔道结构的新型多孔陶瓷。经过近十年的发展加上国家对多孔陶瓷和节能环保相关产业的重视，多孔陶瓷的研究已成为当今一大热点。经过近些年的发展多孔陶瓷的制备工艺已经日渐成熟，多孔陶瓷的生产工艺一般由粉磨、成型、成孔、烘干和煅烧组成，其中成型和成孔是制备多孔材料和影响其性能的关键。泡沫陶瓷除了具有陶瓷本身耐高温、耐腐蚀、强度高、化学性质稳定的特点外，还具有密度小、吸声、热导率低、比表面积高、绿色环保等优点。泡沫陶瓷由于其独特的结构也使得它具有了特殊热学性能、力学性能和电学性能等。

本文以高州洗泥，钠长石，温石英和纯碱为主要原料。SiC为发泡剂，磷酸钠为添加剂，使用发泡法作为造孔方法，压制成型作为成型方法，制备出了热导率在0.2 W/mK左右，抗折强度在4MPa左右，密度低于0.6g/cm³的泡沫陶瓷材料。该泡沫陶瓷材料的基础组成为SiO₂(60wt%),Al₂O₃(30wt%),Na₂O(10wt%)，确定了泡沫陶瓷的最佳工艺制度：烧结温度为1200℃，保温1h;发泡温度为950℃，保温45min。

通过实验比较了AlN和SiC两种发泡剂的发泡效果，结果表明：选用SiC为发泡剂含量且含量为4.5wt%左右时，发泡效果较好。尝试了硼砂和磷酸钠两种添加剂，探究了随添加剂含量增加性能的变化规律，发现磷酸钠添加量为5wt%时得到了体积密度较低，孔分布较均匀的泡沫陶瓷。

通过XRD测试，发现在该体系下的泡沫陶瓷析出的晶相主要为α-石英，并通过XRD图谱发现添加硼砂的样品还析出SiC晶相，说明在添加硼砂的样品中发泡剂未能完全反应。

关键词：泡沫陶瓷，发泡剂，热导率，体积密度

Abstract

   Porous ceramic is a high-temperature firing, the internal full of stomatal structure of the new ceramic materials. The foam ceramic is a macroporous ceramic, it is a common porous ceramic, honeycomb porous ceramic after the development of a three-dimensional channel with a new type of porous ceramic. After nearly a decade of development coupled with the state of porous ceramics and energy conservation and environmental protection related industries, porous ceramic research has become a hot spot today. After several years of development of porous ceramic preparation process has become increasingly mature, porous ceramic production process generally by the grinding, forming, into the hole, drying and calcination, which is formed and into the hole is the preparation of porous materials and affect its performance The essential. Foam ceramic in addition to the ceramic itself has high temperature, corrosion resistance, high strength, stable chemical properties, but also has a small density, sound absorption, low thermal conductivity, high surface area, green and so on. Foam ceramic because of its unique structural night makes it has a special thermal properties, mechanical properties and electrical properties.

     In this paper, Gaozhou washing mud, albite, warm quartz and soda ash as the main raw material. SiC was used as the foaming agent and sodium phosphate as the additive. The thermal conductivity was about 0.2 W / mK, the flexural strength was about 4MPa and the density was lower than 0.6 by using the foaming method as the forming method and the pressing method. G / cm³ of foam ceramic material. (10wt%), the best technological system of the ceramic foam was determined: the sintering temperature was 1200 ℃, the insulation was 1h; the foaming temperature was 950 (60wt%), the content of the foamed ceramic material was 1200 ℃, holding 45min.

The foaming effect of AlN and SiC foaming agent was compared. The results showed that the foaming effect was better when SiC was used as the blowing agent content and the content was about 4.5wt%. The effects of borax and sodium phosphate on the performance of the additive were investigated. It was found that the addition of sodium phosphate had the best flux effect when the amount of sodium phosphate was added, and the uniformity of the bubble was improved.

The crystal phase precipitated in the ceramic foam was mainly α-quartz by XRD, and the XRD pattern was used to find that the addition of borax samples also precipitated the SiC crystal phase, indicating that the foaming agent was not completely reaction.

Key words: foam ceramic, foaming agent, thermal conductivity, bulk density.

目录

摘 要 Ⅰ

Abstract Ⅱ

第1章 绪论 1

1.1泡沫陶瓷的简介 1

1.1.1概述 1

1.1.2泡沫陶瓷的应用 1

1.2泡沫陶瓷的性能指标 3

1.2.1气孔率 3

1.2.2孔的大小和分布 4

1.2.3比表面积 4

1.3泡沫陶瓷的制备工艺 4

1.3.1发泡法 4

1.3.2溶胶-凝胶法 5

1.3.3有机泡沫浸渍法 5

1.3.4冷冻干燥法 6

1.3.5挤压成型法 6

1.4国内外研究现状 6

1.4.1国内现状 6

1.4.2国外现状 7

1.5研究内容与意义 7

第2章 实验 9

2.1实验原料与设备 9

2.1.1实验原料 9

2.1.2实验仪器 9

2.2实验方法 10

2.2.1配方设计 10

2.2.2温度制度的确定 10

2.2.3物料粒度的确定 10

2.2.4探究添加剂用量的影响 11

2.2.5探究发泡剂用量的的影响 11

2.3试样的制备 11

2.3.1泡沫陶瓷的制备工艺流程 11

2.3.2制备过程 11

2.4泡沫陶瓷的性能测试 12

2.4.1体积密度 12

2.4.2热导率 12

2.4.3抗折强度 12

2.5泡沫陶瓷的物相及微观结构测试 12

2.5.1XRD分析 12

2.5.2体视显微分析 13

第3章 实验结果与讨论 14

3.1不同发泡剂实验结果 14

3.2粒度对泡沫陶瓷的影响实验结果 15

3.3不同SiC发泡剂含量的实验结果 16

3.3.1体积密度 16

3.3.2热导率和孔径的分布 17

3.4磷酸钠和硼砂添加剂的实验结果 18

3.5选择温度制度的实验结果 23

3.5.1热分析 23

3.5.2保温时间的确定 23

3.6X射线测试结果 24

3.7性能测试结果 25

第4章 结论 26

参考文献 27

致 谢 29

第1章 绪论

1.1泡沫陶瓷的简介

1.1.1概述

在现实生活中陶瓷材料的种类多种多样，但是在所有的陶瓷的内部均或多或少存在有各种大小不一的气孔。通常情况下我们为了提高陶瓷材料的强度与性能我们要尽可能的减少气孔，使陶瓷材料接近理论密度；但是多孔陶瓷材料恰恰相反，研究者们尽可能的想提高气孔率并想办法控制孔的结构和大小。有人将多孔陶瓷定义为一种经高温烧成，内部富含气孔结构新型的陶瓷材料。现在，多孔陶瓷的气孔率通常为20%~97%^[1]，内部孔道互相连接形成复杂的三维网状迷宫形结构。多孔陶瓷按孔径的大小可以分为微孔陶瓷、介孔陶瓷和宏孔陶瓷，孔的尺寸在2nm以下称为微孔，在2-50nm称为介孔，50nm以上称为宏孔^[2]。泡沫陶瓷就是一种宏孔陶瓷，它是在普通的多孔陶瓷和蜂窝多孔陶瓷后发展起来的一种新型多孔陶瓷。这种泡沫陶瓷具有三维联通孔道结构，气孔率可以达到70%-90%，体积密度一般可以达到0.3-0.6g/cm³^[3]。

我国对于多孔陶瓷的研究是在二十世纪末才开始。经过近十年的发展加上国家对多孔陶瓷和节能环保相关产业的重视，多孔陶瓷的研究已成为当今一大热点。经过近些年的发展多孔陶瓷的制备工艺已经日渐成熟，多孔陶瓷的生产工艺一般由粉磨、成型、成孔、烘干和煅烧组成，其中成型和成孔是制备多孔材料和影响其性能的关键。就成型方法而言目前有手工搓球成型法、成球机成型法、挤压成型法、凝胶注模法和生物模板法等。成孔方法有致孔剂法、颗粒堆积法、发泡法、有机泡沫浸渍法和溶胶—凝胶法、冷冻干燥法等。后面会对泡沫陶瓷的制备工艺作详细介绍。不同的成型和成孔工艺对生产的难易程度、孔的结构气孔率以及多孔材料的最终性能都有较大影响。