原位生长β-氮化硅晶须强韧化微晶玻璃基高温结构/功能一体化材料的形成机理与性能调控

This project takes the demand of national aeronautics and space technology, electronic communications and other fields on advanced high-temperature structure and function-integrated materials as the background, prepared by in-situ grown β-Si3N4 whisker strengthening & toughening glass-ceramics based high-temperature structure and function-integrated materials. The in-situ grown process of β-Si3N4 whisker and crystallization mechanism of microcrystals phase, composite interface formation and function mechanism, strengthening and toughening mechanism, regulation of performance and high temperature applications of in-situ growth of β-Si3N4 whisker strengthening & toughening glass-ceramics based high-temperature structure and function-integrated materials were mainly investigated. Through the design of composition and process, systematic study of the relationship among the components, process and the density of the materials, type, size, distribution, shape and microstructure of crystallite particle in glass-ceramic composites are performed, with exploring the relationship among the composition, process, structure and properties of the in-situ grown β-Si3N4 whisker strengthening & toughening glass-ceramics based high-temperature structure and function-integrated materials. The final controllable preparation technology of the glass-ceramics based high-temperature structure and function-integrated materials with excellent comprehensive properties are obtained, accompanying with establishing the performance index system of these composites, with comparing it with similar materials, in order to make a technical storage for an actual application. The development research of this project shows important practical value and scientific significance for promoting the development and of new type of high-temperature structure and function-integrated materials.

本项目以国家航空航天技术、电子通讯等领域对先进高温结构/功能一体化材料的共性需求为背景，制备原位生长β-氮化硅晶须强韧化微晶玻璃基高温结构/功能一体化材料。主要研究β-氮化硅晶须的原位生长过程和微晶相的析晶机理；原位生长β-氮化硅晶须强韧化微晶玻璃基高温结构/功能一体化材料的复合界面形成及作用机制、强韧化机理、性能调控及高温应用等。拟通过成分与工艺设计，系统研究一体化材料的组成和工艺与致密度、晶相种类、晶粒大小、微晶体分布及形貌的关系，探明原位生长β-氮化硅晶须强韧化微晶玻璃基高温结构/功能一体化材料的组成-工艺-结构与性能之间的相关性。最终获得综合性能优良的微晶玻璃基高温结构/功能一体化材料的可控制备技术，建立性能指标体系，为其实际应用作技术储备。本项目的开发研究对于促进高温结构/功能一体化新材料的开发及其制备科学的发展，有着十分重要的实用价值和科学意义。

本项目研究了原位生长β-氮化硅晶须强韧化微晶玻璃基高温结构/功能一体化材料的组成设计、制备工艺技术及组成-工艺-结构-性能的关系，并获得了其制备技术和性能调控技术。通过组成与工艺优化，实现了原位生长β-氮化硅晶须强韧化微晶玻璃基高温结构/功能一体化材料的可控制备与性能可调，最终制备的原位生长β-Si3N4增强微晶玻璃复合材料的综合性能如下：密度为3.26-3.45 g/cm3，抗弯强度可达648-687 MPa，显微硬度可达13.9-14.7 GPa，断裂韧性为6.4-6.9 MPa·m1/2，弹性模量为216-224 GPa，介电常数为6.2-6.5，25-600℃热膨胀系数为5.25-5.68×10-6/℃。该微晶玻璃基高温结构/功能一体化材料结合了β-氮化硅、微晶玻璃和氮化铝三者的优点，且能够加工成复杂形状的工件，有可能使用在高热导率陶瓷基板以及高端陶瓷零部件等高科技领域。本研究增加了高温结构和功能一体化材料的新品种。已在国际学术期刊发表论文15篇，全部被SCI收录。已申请相关的新材料发明专利6项。已参与编写著作1部，并参加了国际会议1次。而且联合培养了研究生6人。相关研究工作已引起国内外的高度关注，并得到国际同行的肯定。