ZrB2-SiC超高温陶瓷在热震中的强度灾变机制研究

The Reasearch Program is based on ”Toughening mechanism in ZrB2-SiC ultra-high temperature ceramics under thermal shock conditions” ,which is “Cultivating projects” of the major research program of the National Natural Science Foundation of China-” Key basic scientific problems of near-space vehicle”. The project will further study the thermal shock failure micro-mechanism of the The ultra- high temperature ceramic ZrB2-SiC, and discuss microstructure principle that is to improve the thermal shock resistance of ceramic materials. The project will provide the principle guidance to the microstructure design and materials preparation that can be used to improve the thermal shock resistance of ceramic materials. The reasearch topics are as follows: microstructure evolution, crack initiation and propagation of ZrB2-SiC which are under thermal stress generate and process because the thermal shock. Through theoretical model and numerical calculation, the reasearch will establish the fundamental relation between the mechanisms in the material microstructure and mechanical behavior of thermal shock resistance.

本项目在国家自然科学基金委重大研究计划“近空间飞行器的关键基础科学问题”的“培育项目”——“热冲击条件下超高温陶瓷ZrB2-SiC的强韧化机制研究”的基础上，进一步研究ZrB2-SiC超高温陶瓷热震失效微观机制，深入探讨在热冲击下提高陶瓷材料抗热冲击性能的微结构原理，为提高陶瓷抗热震性的微结构设计和材料制备提供原理性指导。本课题的主要研究内容包括：实验研究ZrB2-SiC系列陶瓷在热冲击下其热应力生成和作用过程中的微结构演化、裂纹萌生和扩展过程，通过理论建模和数值计算，确立材料微结构与抗热冲击力学行为之间的根本关联机制。

本项目在国家自然科学基金委重大研究计划“近空间飞行器的关键基础科学问题”的“培育项目”——“热冲击条件下超高温陶瓷ZrB2-SiC的强韧化机制研究”的基础上，进一步研究高温环境下陶瓷材料在热震过程中发生强度灾变失效的物理机制，重点研究了陶瓷材料的特征长度和加热温度两个外部因素对材料热震破坏的影响,获得了陶瓷材料热震破坏的临界曲线,并通过实验证实了所获结果。发表SCI论文两篇，另外两篇在审。