Abstract In this study, an efficient method was proposed to establish 3D microstructure model of a Si3N4-bonded SiC ceramic refractory with SiC high volume ratio particles and its failure mechanism under thermal shock was studied based on the established microstructure model. The proposed modeling method based on modified 3D Voronoi tessellation method and “precise shrinkage ratio method” was able to establish 3D geometric model of a SiC ceramic refractory with SiC high volume fraction particles more quickly than usual methods. The modified 3D Voronoi tessellation method generated Voronoi polyhedrons (VPs) limited in finite space perfectly. The proposed “precise shrinkage ratio method” achieved a precise volume fraction of SiC particles in the established microstructure model. The crack initiation and propagation under thermal shock were calculated by employing the extended finite element method (XFEM) on the established microstructure model. The results showed the failure mode on micro-scale clearly and efforts of interface strength on the failure mode were also explored. The proposed modeling method was especially suitable for establishing 3D microstructure models of ceramic composites or isotropic metal-ceramic particle composites with high volume fraction particles and extended the use of VPs.

中文翻译：

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含SiC高体积比颗粒的Si3N4结合SiC陶瓷耐火材料的3D微观结构模型和热冲击失效机理

摘要 本研究提出了一种建立含SiC高体积比颗粒的Si3N4结合SiC陶瓷耐火材料3D微观结构模型的有效方法，并基于所建立的微观结构模型研究了其在热冲击下的失效机理。所提出的基于改进的 3D Voronoi 镶嵌法和“精确收缩率法”的建模方法能够比通常的方法更快地建立具有 SiC 高体积分数颗粒的 SiC 陶瓷耐火材料的 3D 几何模型。改进的 3D Voronoi 曲面细分方法完美地生成了有限空间中的 Voronoi 多面体 (VP)。提出的“精确收缩率方法”在建立的微观结构模型中实现了精确的 SiC 颗粒体积分数。采用扩展有限元法（XFEM）对建立的微观结构模型进行热冲击下裂纹萌生和扩展的计算。结果清楚地显示了微观尺度的失效模式，并且还探讨了界面强度对失效模式的影响。所提出的建模方法特别适用于建立具有高体积分数颗粒的陶瓷复合材料或各向同性金属-陶瓷颗粒复合材料的 3D 微观结构模型，并扩展了 VPs 的使用范围。