尺寸效应对纳米钛酸钡陶瓷力学性能的影响研究

项目名称： 尺寸效应对纳米钛酸钡陶瓷力学性能的影响研究

项目编号： No.50872093

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 邓湘云

作者单位： 天津师范大学

项目金额： 38万元

中文摘要： 近年来国内外钛酸钡陶瓷尺寸效应研究的核心内容主要围绕晶粒尺寸对于介电性能、相变和显微结构的影响，纳米尺寸效应对钛酸钡陶瓷力学性能的影响研究还很少。本项目实验方面利用两段式无压烧结和放电等离子体烧结工艺分别制备出一系列不同晶粒尺寸的高密度纳米晶钛酸钡陶瓷，测试不同晶粒尺寸钛酸钡陶瓷的硬度、弹性模量和蠕变等力学性能；理论方面通过研究不同晶粒尺寸钛酸钡陶瓷的微观结构、原子在晶粒与晶界间的扩散、化学键的变化，揭示尺寸效应对纳米晶钛酸钡陶瓷力学性能的影响。从第一性原理分子动力学的角度结合密度泛含以及界面协调应变模型等理论，从化学键密度、键长、化学势、电子能带结构引起的应力场等理论研究入手，揭示不同晶粒尺寸钛酸钡陶瓷晶粒扩散、晶界结构对力学性能的影响机理和控制规律。 该研究对于钛酸钡纳米晶陶瓷材料在新型微电子器件中的应用具有重要的理论和实际意义，同时也为纳米晶陶瓷理论体系的建立和完善提供科学依据。

中文关键词： 钛酸钡陶瓷；力学性能；尺寸效应；微观结构；制备

英文摘要： In recent years，the core research contents of size effect of BaTiO3 ceramics focuses on grain size effect for the dielectric properties，phase change and the influence of the microstructure. But size effect study of the mechanical property of nanocrystalline BaTiO3 ceramics is rare. In the project, the bulk dense nanocrystalline BaTiO3 ceramics at various sizes have been successfully prepared by the two step sintering and the spark plasma sintering process, respectively. The mechanical properties of hardness, elastic modulus and creep were measured. In theory, the effect of the hardness properties of nanocrystalline BaTiO3 ceramics was reveled by the size effect, through the study of microstructure, the diffusion of atomic between grain and grain boundary and the change of the chemical bonds of nanocrystalline BaTiO3 ceramics. Based on the primary principle of molecular dynamics with density functional, interface coordination models theory, chemical bonds density, key long, chemical potential, stress field caused by the electronic band structure, the influence mechanism and control laws of different grain size BaTiO3 ceramics grain diffusion and structure of grain boundaries were revealed. The research has important theoretical and practical significance for nanocrystalline BaTiO3 ceramics materials in new application of microelectronics devices. At the same time, it also provides the scientific basis for the establishment and perfection of nanocrystalline ceramic theoretical system.

英文关键词： BaTiO3 ceramics; mechanical property; size effect; microstructure; preparation