高性能钛酸钡基PTCR陶瓷材料的研究

【作者】 贾金亮；

【导师】 杨孟林； 畅柱国；

【作者基本信息】 西北大学 ， 物理化学， 2005， 硕士

【摘要】 钛酸钡系列电子陶瓷是近几十年发展起来的新型现代功能陶瓷,目前已成为现代功能陶瓷中最为重要的一类,是电子陶瓷元器件的基础母体原料,被称为电子陶瓷的支柱。自从人们在烧结的过程中发现钛酸钡材料及掺杂影响其介电性以来,关于掺杂钛酸钡的制备和电性能的研究就成为无机非金属材料中的一个热点领域。我国在这方面的工作及相关高性能电子产品的开发与国外相比差距较大,还有大量的工作有待开展。所以,本论文考虑从制备出高性能钛酸钡基PTCR陶瓷材料的角度出发,采用溶胶-凝胶一步法合成技术和国产原料制备了钛酸钡基PTCR纳米晶粉体及其陶瓷材料,分析了各掺杂元素和烧结工艺对陶瓷材料性能的影响,并采用TG-DSC、XRD和SEM对粉体和陶瓷的相组成以及显微结构进行表征。 本论文首先采用正交试验成功地设计和优化了制备PTCR陶瓷材料的配方,并通过因素的位级趋势分析法讨论了Ti/Ba摩尔比、Mn、Y、Ca和Pb五因素对陶瓷材料的影响。 其次,本论文进行了Ca、Mn、Ti/Ba摩尔比和Si掺杂实验,详细讨论了它们的含量和烧结工艺对陶瓷材料电性能的影响,并制备出了低电阻率高耐压的PTCR陶瓷材料。 此外,论文还尝试了以硼酸三丁酯为掺杂剂向陶瓷材料中掺入硼元素,并研究了它对陶瓷材料电性能的影响。 本实验通过对陶瓷材料组成和工艺条件的优化,最终制备出了居里温度（Tc）为100℃,室温电阻率（ρ_室）～18Ω·cm,温度系数(α₃₀)～17%·℃^-1,耐电压（V_b）>195V·mm^-1,电阻率突变(ρ_max/ρ_min)>10⁶,并且耐工频电压和耐工频电流都达到要求的高性能PTCR陶瓷材料。更多还原

【Abstract】 Barium titanate ceramics, which have been developed in several decades years, are a kind of new functional ceramics. At present, they have been one of the most important functional ceramics and used as the basic raw materials in the composition of ceramic capacitors. The research of preparation and properties of doped barium titanate has been a focal point in the field of inorganic nonmetal materials since the dielectric properties of barium titanate materials were discovered in the sintering process.However, the research of barium titanate and electric materials with high performance was began only in recent years in our country and there is a lot of work to do. In this paper, according to the preparation of BaTiO₃ - based PTCR ceramic materials with high performance, nanocrystalline BaTiO₃ - based PTCR powder and its ceramic materials were prepared using the synthesis method of sol-gel in one step and China-made raw materials. During the experiment, the influence of every doped element and sintering process on the properties of ceramic materials was analysed, and the powers and ceramics were characterized by TG-DSC, XRD and SEM.Firstly, the orthogonal experiment was successfully used to design and optimize components of PTCR ceramic materials. The influence of five factors including Ti/Ba, Mn, Y, Ca and Pb on ceramic materials was discussed by the orthogonal experiment.Secondly, doped experiments of four factors including Ca, Mn, Ti/Ba and Si have been completed. The influence of their contents and sintering process in the experiments on the properties of ceramic materials was discussed in detail. High performance BaTiO₃-based PTCR ceramic materials with low resistivity were finally obtained.In addition, a try of using tributyl borate（B） as dopant was tested, and the influence of that on the properties of ceramic materials was discussed.Finally, high performance PTCR ceramic material with a curie temperature （T_c） of 100°C, a resistivity at room temperature（ ρ_室） of ¹8Ω.cm, a temperaturecoefficient of resistivity (α₃₀) of ¹7%.°C^-1, a withstand voltage intensity（V_b） of>195V-mm"1 , a resistivity step ratio （pmax//?min） of > 106 , excellent overvoltagewithstanding and over-current withstanding was obstained by optimizing doped elements and sintering process.更多还原