冲击加载下蓝宝石单晶热点辐射谱及其时空演化特性研究

Sapphire single crystal is typical high strength transparent material and important window used in dynamic loading experiments, the light radiation and spatial-temporal evolution characteristics of hot spots in sapphire single crystal are of great significance in the precision shock temperature experiment and study of dynamic deformation mechanism of high strength materials. In this project, we will mainly apply time-resolved spectral imaging method combined with macro wave profile measurements to carry out the following research: 1. developing time-resolved multi-wavelength spectral imaging technology in dynamic loading experiments, obtain the distribution image, radiation spectrum and spatial-temporal evolution characteristics of hot spots, realize the in-situ observation and characterization. 2. selecting appropriate model to describe the radiation characteristics and obtain the temperature of hot spots, combining with the theoretical calculation to explore the relationship between the hot spots and the high pressure melting property. 3. combining with wave profile measurement, to explore the correlation rule of hot spots evolution and dynamic deformation characteristic.Through the implementation of this project, in-situ observation technology with spatial-temporal resolution of localized hot spots in the transparent samples can be established, and the mesoscopic response characteristic of sample can be obtained. Moreover, this project will help the dynamic research goes into the mesoscopic level, which can provide important references for studying the principle of dynamic response.

作为典型的高强度透明材料和动态加载实验中重要的窗口，蓝宝石单晶内部局域化热点的光谱辐射及其时间、空间演化特性在冲击温度测量实验及高强度材料动态变形机制研究中具有重要意义。本项目拟采用具有时间分辨的面成像辐射测量方法结合宏观波剖面测量，开展如下研究：1.发展动态加载下具有时间分辨的多波长面成像技术，获得蓝宝石单晶内部热点分布图像、辐射光谱及其随时间的演化，实现对热点特性的原位观测表征。2.选取合适的模型描述热点辐射特性，确定热点温度，结合理论计算获取热点与高压熔化特性的关系。3.结合宏观波剖面测量，探索热点演化与动态变形特性的关联规律。通过本课题的研究，可以建立动态加载下对透明样品内部局域热点时空分辨的原位观测技术，获取样品细观响应特性信息。课题研究结果有助于动态在线研究工作深入至细观层面，可为材料宏观动态响应的细观机制研究提供重要参考和依据。

作为典型的高强度透明材料和动态加载实验中重要的窗口，蓝宝石单晶内部局域化热点的光谱辐射及其时间、空间演化特性在冲击温度测量实验及高强度材料动态变形机制研究中具有重要意义。本项目发展了具有时间分辨的面成像瞬态测量技术，获得了冲击加载下a向及c向蓝宝石单晶的热点分布及其时间、空间演化图像。过对热点的直接观测表明其辐射满足黑体特征，热点温度与蓝宝石高压融化温度基本一致。冲击加载下蓝宝石单晶热点的形成系材料内部的剪切高温导致，受压所材料的非均匀变形导致剪切带及热点的局域化现象，受压缩层对时间增长增厚，视场中热点面密度亦随时间增加，占空比增大。建立了高强度材料局域化热点辐射模型，定性解释了宏观高温计测量中福亮度及发射率随时间增大的现象。 课题研究结果可为冲击压缩下高强度透明材料光学特性及其机制的研究提供参考，同时可为透明材料冲击温度测量方法和模型的优化提供支撑， 有助于动态在线研究工作深入至细观层面。