摘 要

为了有效解决柔性石墨基密封材料因高温氧化造成密封失效的问题，采用膨胀蛭石制备耐高温密封材料，系统研究了高膨胀率蛭石蠕虫的制备，密封材料的成型方法和原料组成对密封材料性能的影响。通过膨胀率和脆性指标考察高温法和化学法制备膨胀蛭石的效果，高温法试验结果表明，粗粒蛭石膨胀效果优于细粒蛭石，随着膨胀时间的延长，膨胀蛭石脆性指标下降；化学法试验结果说明，高浓度双氧水能有效提高蛭石膨胀倍数，化学法对蛭石脆性指标影响不大；论文探索了模压成型、沉降成型和刮刀成型对密封材料成型效果的影响，刮刀成型效果最佳，能够制备结构致密，性能良好的密封材料；密封材料性能测试表明，不同物料组成对密封材料的性能均有一定程度的影响，其烧失量均为10%左右，主要为胶粘剂的烧蚀，压缩率＜30%，回弹率＞30%，性能指标优于同类柔性石墨密封材料。

关键词：膨胀蛭石；密封垫片；高温法；化学法。

Abstract

In order to effectively solve the problem of sealing failure caused by high temperature oxidation of flexible graphite base sealing material,we using the vermiculite for preparing high temperature resistant sealing material to systematically studied the preparation of high expansion ratio of vermiculite worm,the molding method of sealing material and the effect of composition of raw materials on properties of sealing materials.Through the expansion ratio and brittleness index to investigating the effect of high temperature and chemical preparation of vermiculite.Test results of the high temperature method shows that the coarse vermiculite is better than fine vermiculite and with the extension of the expansion time,vermiculite brittleness index has decreased.Test results of chemical method shows that the high concentration of hydrogen peroxide can effectively improve the vermiculite expansion ratio ,but has little effect on the brittleness index of vermiculite.In this paper, the effects of compression molding,settlement molding, and scraper forming for the sealing materials were studied,and the effect of scraper forming is the best,which can preparing for a sealing material that has compacted structure and good performance.Seal material performance test shows that different material composition has a certain degree of influence on the performance of the sealing material,and their loss of ignition are all about 10%,most of which are the ablation of adhesive.And their compression ratio are less than 30%，with rebound rate more than 30%,so that their performance index are superior to similar flexible graphite sealing material.

Key word： Exfoliated vermiculite,Seal gasket,Thermally,Chemically.目录

1.1蛭石的简介 6

1.1.1 蛭石的结构及组成 6

1.1.2 蛭石的物化特性 7

1.1.3 膨胀蛭石材料 8

1.2 矿物密封垫片研究现状 9

1.2.1 密封垫片的分类 9

1.2.2 密封垫片的应用 11

1.2.3 密封技术的研究现状 13

1.3 矿物密封垫片存在的问题 13

1.4研究课题的目的及意义 13

二、试验原料及研究方法 15

2.1 试验原料 15

2.1.1 试验原料来源 15

2.1.1 XRF分析 15

2.1.2 XRD分析 15

2.1.3 DSC-TG分析 16

2.2 实验试剂及仪器 17

2.2.1 试验药剂 17

2.2.2 试验仪器 17

2.3试验研究方法 18

2.3.1 膨胀率测定 18

2.3.2脆性程度分析 19

2.3.3 耐高温性能测试 19

2.3.4 压缩回弹性测试 19

三、耐高温蛭石基密封材料的制备 20

3.1高温法膨胀和化学法膨胀对蛭石的影响 20

3.1.1 高温法对蛭石膨胀率的影响 20

3.1.2 高温法对膨胀蛭石脆性的影响 21

3.1.3 化学法对蛭石膨胀率的影响 23

3.1.4化学法对膨胀蛭石脆性的影响 24

3.2耐高温蛭石基密封材料的成型 25

3.2.1 干法成型 25

3.2.2 沉降成型 26

3.2.3 刮刀成型 27

3.3 耐高温蛭石基密封材料的制备 29

3.3.1 高温膨胀蛭石制备密封材料 29

3.3.2 化学膨胀蛭石制备密封材料 30

3.3.3 混合膨胀蛭石制备密封材料 30

3.4 本章小结 30

四、结论 32

五、参考文献 33

一、绪论

1.1蛭石的简介

1.1.1 蛭石的结构及组成