碳化硼(B4C)作为重要的工程材料被广泛应用于航空航天和防弹装甲等领域。然而B4C致密化困难，韧性和强度较低影响其进一步应用与发展。利用熔体生长技术定向凝固制备B4C基共晶复合陶瓷为该材料致密化与强韧化提供了重要途径。为了控制凝固组织并提升力学性能，有必要深入理解其凝固行为和生长机理。本项目拟采用高梯度光悬浮区熔定向凝固技术，制备致密度高、缺陷可控和组织均细化的B4C基共晶复合陶瓷(B4C-TiB2，B4C-SiC)。结合高通量SEM图像采集与深度学习图像识别技术，实现凝固组织跨尺度表征与共晶特征尺寸定量分析，揭示共晶形貌与尺寸演化规律。通过三维组织重构与分析，揭示共晶组织空间生长特征与相尺寸调整方式，阐明高熔化熵小平面相共晶内禀生长机制。在此基础上，初步建立成分-组织-力学性能跨尺度原位统计映射关系，为开发新一代强韧化B4C基共晶复合陶瓷，丰富和拓展共晶凝固理论，提供理论基础和数据支撑。

Boron carbide (B4C) is widely used as an important engineering material in the fields of aerospace and body armor, etc. However, further application and development of B4C are limited severely due to the difficulty in densification and its low fracture toughness and strength. The in-situ fabrication of B4C-base eutectic composite ceramics through melt growth directional solidification technique provides an important method for strengthening, toughening, and densification of materials. For microstructures control and mechanical properties improvement, deeply understanding of solidification behavior and growth mechanism of B4C-base eutectic composite ceramics is very essential. In this project, B4C-base (B4C-TiB2, B4C-SiC) eutectic composite ceramics with high densities, controllable defect and homogeneously refined microstructures are directionally solidified by optical floating zone melting with high temperature gradient. Based on high-throughput SEM image acquisition and deep learning image recognition technology, trans-scale characterization of solidification microstructures and quantitative analysis of eutectic characterized dimensions will be performed. Accordingly, the evolution of eutectic morphologies and sizes will be revealed. Through three-dimensional microstructure reconstruction and analysis, spatial growth characteristic of eutectic microstructure and adjustment of phase size will be revealed and intrinsic growth mechanism of faceted eutectics with high melting entropies will be clarified. On this basis, the trans-scale original position statistic mapping relationship of composition, microstructure, and mechanical property will be preliminarily established. This project will provide theoretical basis and data support for development of a new generation of B4C-base eutectic composite ceramics with strengthening and toughening properties, and meaning while enriching and expanding eutectic solidification theory.