【作者】 张昌松；

【导师】 田长生；

【作者基本信息】 西北工业大学 ， 材料加工工程， 2006， 博士

【摘要】 随着世界各国对环境保护的重视，势必采用无铅的压电材料来替代传统的含铅压电陶瓷材料，以减少环境污染，因此压电陶瓷的无铅化就成为压电陶瓷发展的趋势。本文选择钛酸铋钠—钛酸铋钾（NBT-KBT）无铅陶瓷研究体系，采用RTGG（Reactive Templated Grain Growth）法以Bi₄Ti₃O₁₂微晶为模板制备NBT-KBT无铅压电织构陶瓷，主要研究模板材料的选择与制备工艺、织构陶瓷的成型设备与方法、NBT-KBT陶瓷的显微组织结构和电性能之间的关系等，制备出电性能良好、各向异性显著的NBT-KBT无铅压电织构陶瓷。 论文结合RTGG和TGG（Templated Grain Growth）的工艺特点，分析了制备织构陶瓷微晶模板的选择原则，确定了适用于制备NBT-KBT织构陶瓷的模板种类，通过对几种满足模板选择原则的典型模板材料进行逐个分析，最终确定出了具有高的生长各向异性的Bi₄Ti₃O₁₂微晶作为制备NBT-KBT织构陶瓷的模板；通过对现有陶瓷成型工艺方法的比较，选择出适用于制备织构陶瓷的成型工艺方法，同时自行研制了实验室用于制备织构陶瓷的设备，该设备目前已申报国家实用新型专利（申请号：200520078348．9）。 采用熔盐法制备了Bi₄Ti₃O₁₂微晶粉体，研究了制备工艺参数与Bi₄Ti₃O₁₂微晶的形貌和尺寸之间的关系。结果表明，Bi₄Ti₃O₁₂微晶粉体的显微组织形貌和尺寸与烧结温度、熔盐量、保温时间等工艺参数关系密切。在发现Bi₂O₃的过量加入对Bi₄Ti₃O₁₂微晶粉体的形貌起了决定性的作用后，系统的研究了Bi₂O₃过量的程度和制备工艺参数对Bi₄Ti₃O₁₂微晶粉体显微组织形貌的影响，最终实现了通过工艺参数的设定对其显微组织形貌和尺寸的控制。采用熔盐法成功地制备了适合流延工艺要求的纯Bi₄Ti₃O₁₂微晶，微晶尺寸均匀，分散性好，直径与厚度比大，直径为8～10μm，厚度为1～2μm。采用此粉体制备了Bi₄Ti₃O₁₂陶瓷，研究了该陶瓷的电性能与工艺参数之间的关系，结果显示该陶瓷已经显示出了各向异性的特性。 采用传统方法制备出NBT-KBT陶瓷，确定了其准同型相界，而组分为0.84NBT-0.16KBT的陶瓷位于准同型相界附近，且具有较佳的压电性能；以0.84NBT-0.16KBT组分为研究对象，研究基体中加入不同量Bi₄Ti₃O₁₂微晶烧结后所制备NBT-KBT陶瓷的显微组织结构与电性能，优化了烧结工艺的同时确定出Bi₄Ti₃O₁₂微晶的最佳加入量。 分别采用干法和湿法两种流延方法和RTGG工艺制备了NBT-kBT织构陶瓷，研究了烧结温度对织构陶瓷烧结行为、织构度和显微组织结构的影响规律，制备出了NBT-KBT织构陶瓷，解决了湿法流延中烧结后样片的变形问题。结果表明：NBT-KBT织构陶瓷的烧成温度范围只有10～20℃，其介电性能、压电性能和铁电更多还原

【Abstract】 It is imperative under the situation of increasing enviromental protection worldwide that investigating of lead-free piezoelectric ceramics to replace traditional piezoelectric ceramics is the latest trend in piezoelectric development. In this paper, as a lead-free material, sodium bismuth titanate-potassium bismuth titanate （NBT-KBT） ceramics was fabricated by Reactive Templated Grain Growth （RTGG） technique with the Bi₄Ti₃O₁₂ particles as template. Effects of processing parameters, Such as template materials selection and processing, preparation equipment and method of textured ceramics, relationship between microstructure and electric properties of NBT-KBT ceramics were investigated. NBT-KBT textured ceramics with better properties and strong anisotropy was prepared.The principle of selecting template particles to prepare textured ceramics was analyzed according to technic properties of RTGG and TGG, templated type of adapting to prepare NBT-KBT textured ceramics was confirmed. Plated-like Bi₄Ti₃O₁₂ template particles with high aspect ratio was used to prepare NBT-KBT textured ceramics; according to comparing the current ceramics preparation method, molding technics for preparing NBT-KBT textured ceramics was optimized and the molding equipment was designed, it had been applied for national patent of practicality new pattern. （application code: 200520078348. 9）Anisotropic Bi₄Ti₃O₁₂ particles were synthesized by molten salt process. Effect of technique and processing parameters on the morphology of Bi₄Ti₃O₁₂ particles were also investigated in detail. They were determined by the sintering temperature, molten salt content and soaking time. Excessive Bi₂O₃ content played an important role in morphology and scale of Bi₄Ti₃O₁₂ particles, so effect of the degree of excessive Bi₂O₃ content and processing parameters on the morphology and scale of Bi₄Ti₃O₁₂ particles were investigated in particular. Pure Bi₄Ti₃O₁₂ particle powders, which possess high aspect ratio, were synthesized by molten salt process. The obtained pure Bi₄Ti₃O₁₂ particle powders are very suitable for tape-casting. The average size of pure Bi₄Ti₃O₁₂ particles is 8～10μm in diameter and 1～2μm in thickness. Based on this particles, Bi₄Ti₃O₁₂ ceramics with anisotropy was prepared, relationship between electric properties and process parameter were investigated.NBT-KBT ceramics was prepared by traditional process, and the morphotropic phase boundary （MPB） was confirmed, the component of 0.84NBT-0.16KBT ceramic is closed to MPB and has better piezoelectric properties; Effects of template Bi₄Ti₃O₁₂ concentration on the microstructure and piezoelectric properties of NBT-KBT ceramic were studied. The processing parameters were optimized.The textured NBT-KBT ceramics was fabricated by dry tape-casting method and更多还原