摘要:本文采用了燃烧法制备铈全取代锆得到的铈酸镧陶瓷粉末,考察了温度,时间对陶瓷粉末性能的影响;考察掺杂不同含量的铈对陶瓷粉末性能的影响。用X-射线衍射仪(XRD)、扫描电子显微镜(SEM)、电子能谱仪(EDS)、热膨胀仪对样品的结构、微观形貌、成分和热膨胀系数进行表征。结果表明当用燃烧法在甘氨酸的摩尔量与锆酸镧和铈酸镧的摩尔量之和之比为2:1,反应温度为700℃,反应时间为5h的条件下,能制备出晶体结构完整的La2Zr2-xCexO7(0≤x≤1.4)陶瓷粉。与锆酸镧陶瓷粉进行对比发现,由于Ce离子半径比Zr离子半径大,因此Ce元素的掺杂会使陶瓷粉平均径粒增大;粉体不易烧结致密;可以有效地削弱La2Zr2O7陶瓷的离子键,提高热膨胀系数。22727
毕业论文关键词:锆酸镧;燃烧法;稀土掺杂
Abstract
In this paper, La2Ce2O7 powder was prepared by combustion method which cerium fully substitute for zirconium, and study the effects of temperature and time on the ceramic powder properties; study the effects of doping different amount of ceriumon the ceramic powder properties. The structure, morphology, compositionand and thermal expansion coefficient of ceramic powder were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer and the dilatometer determination. The results showed that when the molar amount of glycine is 2 times of the molar amount of lanthanum nitrate and zirconium nitrate, the reaction temperature of 700℃, the reaction time of 5h, the crystal structure of La2Zr2-xCexO7(0≤x≤1.4) ceramic powder can be prepared. Compared with the La2Ce2O7 ceramic powder , since the ionic radius of Ce is larger than the ionic radius of Zr, the Ce-doped in La2Ce2O7 ceramic powder can increase an average particle diameter; powder will be difficult to densification; weaken the ceramic ioni cbond of La2Zr2O7 effectively to improve the the rmalexpansion coefficient.
Keywords: Lanthanum zirconate ; Combustion method;Rare-earth doping
目录
1前言 1
1.1课题研究的背景 1
1.2热障涂层的研究进展 1
1.3锆酸镧的结构与性能 2
1.4.2锆酸镧的晶体结构 2
1.4.3锆酸镧的热物理性能 3
1.4.4锆酸镧的力学性能 4
1.4.5锆酸镧的热稳定性 5
1.4锆酸镧粉末的制备工艺 6
1.4.1固相反应法 6
1.4.2溶胶凝胶法 6
1.4.3沉淀法 7
1.4.4熔盐法 7
1.4.4熔盐法 8
1.4.5燃烧法 8
1.5稀土掺杂Zr位研究进展 10
1.5.1 Zr位全取代的物质及性能 10
1.5.2 Zr位部分取代的物质及性能 11
1.6本文研究内容及意义 12
1.6.1本文研究的内容 12
1.6.2本文研究的意义 12
2实验部分 13
2.1主要实验试剂与仪器 13
2.1.1主要实验试剂 13
2.1.2主要实验仪器 13
2.2锆酸镧的制备 13
2.3铈酸镧反应温度的选择 14
2.4铈酸镧反应时间的选择 14
2.5掺杂铈含量的选择 14
2.6粉体的性能测试及表征 14
2.6.1粉体结构的分析 14
2.6.2粉体微观形貌的观察 14
2.6.3粉体成分的分析 14 铈掺杂的锆酸镧陶瓷粉制备工艺的研究:http://www.751com.cn/huaxue/lunwen_15466.html