SrAl2Si2O8增强h-BN复相陶瓷在动态载荷及热冲击作用下的响应行为与损伤机理

六方氮化硼(h-BN)陶瓷具有良好的耐高温、抗热震、绝缘性以及机械加工性能，在冶金、电子、化工以及空天飞行器用抗高温、高速介质冲击防护构件中具有广阔的应用前景。但是材料本身的强度还有待提高，在动态载荷和热冲击条件下的组织和性能演化规律还不明确。针对此问题，本项目拟采用溶胶-凝胶法引入SrAl2Si2O8为增强相，采用热压烧结工艺制备BN-SrAl2Si2O8复相陶瓷，探讨成分、制备工艺对复相陶瓷组织结构、力学、热物理性能的影响规律及强韧化机理；阐明BN-SrAl2Si2O8复相陶瓷在高温下的动态力学行为及破坏机理；将实验测试与有限元模拟结合，阐明复相陶瓷在热冲击作用下的显微组织结构和性能的演化规律，揭示其热冲击损伤机理。本项目的完成将为氮化硼基复相陶瓷的制备和性能优化设计提供有效途径，并进一步完善氮化硼陶瓷在高温动态力学、热冲击损伤领域的基础理论，具有重要的学术价值和潜在的工程应用前景。

Hexagonal boron nitride (h-BN) ceramics possess many prominent properties, including high temperature resistance, thermal shock resistance, good insulation and machinability, etc. Due to this combination of properties, h-BN ceramics have wide potential applications in the field of metallurgy, electronics, chemical engineering and protection components for aerospace vehicles. However, the strength of the h-BN ceramics needs to be improved, and the evolution of microstructure and properties under the dynamic compressive and thermal shock environments require further investigations as well. In this project, the SrAl2Si2O8, acting as a reinforcement phase, will be combined with h-BN via sol-gel method, and then hot-press sintered to obtain the BN-SrAl2Si2O8 composite ceramics. The purpose of our research is to systematically investigate the influence of composition and preparation process on microstructure, mechanical and thermophysical properties of the composite ceramics. The strengthening and toughening mechanisms will be analyzed and discussed in detail. Based on the results, the dynamic mechanical behavior and damage mechanism of the composites ceramics at high temperature will be revealed. Furthermore, the experiments and finite element simulation will be combined in this research to elucidate the evolution of microstructure and properties of composite ceramics under thermal shock conditions and reveal the thermal shock damage behavior and its mechanism. The accomplishment of this project will provide theoretical and technical supports for the preparation and optimized performance design of BN-based composite ceramics, and further improve the basic theory and their engineering applications targeted for high temperature dynamic compressive and thermal shock damage environments.