【作者】 王念；

【导师】 周健；

【作者基本信息】 武汉理工大学 ， 材料学， 2002， 硕士

【摘要】 本文系统论述了微波烧结的基本原理、特点和研究现状，介绍了典型的微波烧结设备和本实验所采用的微波烧结装置，并着重论述了微波烧结设备的核心组成部分——烧结谐振腔。详细介绍了PLZT陶瓷的结构、性能和制备方法，并着重介绍了在光电领域有重要应用并已被证明透光性能最好的组成为9／65／35的PLZT铁电陶瓷。 决定PLZT铁电陶瓷透光性能进而扩大其应用范围的关键因素是PLZT原料的高纯度及烧结后PLZT样品的高致密度。因此本研究着重从这两方面进行了探讨。本研究采用了部分共沉淀法这一化学方法来合成PLZT原料，结果表明用这一方法得到的PLZT原料无论是纯度还是粒度等方面都达到了制备PLZT铁电陶瓷的要求。微波的快速烧结能降低反应活化能并促进晶界的扩散，从而有助于获得高致密度的PLZT陶瓷；用自行研制的微波烧结系统对如何提高PLZT铁电陶瓷的致密度开展了研究。在实验过程中，通过对微波烧结升温速率、烧结温度、烧结气氛和保温时间等工艺参数的控制和调整，探索了提高微波烧结组成为9／65／35的PLZT铁电陶瓷的致密度的工艺参数。本研究还着重探讨了PbO对PLZT陶瓷致密度的影响机制。研究发现，PbO在PLZT铁电陶瓷的致密化过程中具有很重要的作用。PLZT体系中低熔点PbO的存在，一方面容易在烧结过程中形成液相，加快晶粒的重排和传质过程的进行，以促进PLZT陶瓷的致密化进程，另一方面也会因为挥发而留下气孔，从而降低PLZT陶瓷的致密度，甚至会因此而造成PLZT组成上的偏差。 对微波烧结的PLZT铁电陶瓷，分别用X衍射(XRD)和扫描电镜(SEM)对PLZT陶瓷进行了表征。结果表明，通过对微波烧结工艺的改进能够有效控制烧结过程中PbO的挥发，促使样品中气孔的充分排出，从而有利于获得晶粒细小均匀并具有较高致密度的PLZT铁电陶瓷。更多还原

【Abstract】 The research discussed the fundamental,characteristics and research status systematically,and introduced a typical microwave sintering system and the equipment that be used in the research briefly. It emphasized the key part of the microwave sintering system,namely resonance cavity. And also it introduced the structure,performances and preparation of PLZT ceramics in detail. And introduced emphatically the 9/65/35 PLZT ferroelectrics ceramics,which it had been proved that its transparence is the best of all PLZT ferroelectrics ceramics that has important applications in the photoelectric field.The key factors that determine the transparent performance of PLZT ceramics to extend its application range are the highly pure PLZT raw materials and the high density of PLZT ceramics,so the research mainly focused on two sides. The research adopted the partial co-precipitation method to gained the highly pure PLZT raw materials. The recent research showed that rapid sintering of microwave sintering reduces the activation-energy and accelerates the diffuse the crystal boundary and help to improve the density of PLZT. The research used the domestic microwave sintering system to investigate how to improve the density of the 9/65/35 PLZT ceramics. In the course of the experiments,we controlled and adjusted the technique parameters of the sintering PLZT ferroelectrics ceramics,such as the raising speed of microwave sintering,the sintering temperature,the sintering atmosphere and the time of heat preservation. The research mainly investigated the effect mechanism of PbO in the density of PLZT. The research was shown that PbO has very important effect in the density of PLZT ceramics. Because in PLZT system,PbO has a low melting point,it is easy to volatilize,and it can form liquid-phase during sintering,so the transfer-particle process and the arrange of particle is accelerated. These all improve the PLZT ceramics density,on the other hand if the volatilization is excessive,the pore will increase so the density decreases,even make the error in the composition of PLZT.The PLZT ceramics was characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM). The experimental results show that the improved microwave sintering technique can control the volatilization of PbO to improve the remove of the pore,so can gained the fine uniform crystal and high dense PLZT ferroelectrics ceramics.更多还原