Li Yilin, Chen Shujian, Duan Wenhui, Yan Wenyi
Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia.
School of Civil Engineering, The University of Queensland, St. Lucia, QLD 4072, Australia.
Phys Rev E. 2021 Jul;104(1-2):015316. doi: 10.1103/PhysRevE.104.015316.
A descriptor-based method combined with a partition approach is proposed to reconstruct three-dimensional (3D) microstructures based on a set of two-dimensional (2D) scanning electron microscopy (SEM) images. The features in the SEM images are identified and partitioned into small features using the watershed algorithm. The watershed algorithm first finds the local gray-level maxima, and partitions the features through the gray-level local minima. The 3D size distribution and radial distribution of the small spherical elements are inferred, respectively, based on the 2D size distribution and radial distribution using stereological analysis. The 3D microstructures are reconstructed by matching the inferred size distribution and radial distribution through a simulated annealing-based procedure. Combining with the proposed partition approach, the descriptor-based method can be applied to complex microstructures and the computational efficiency of the reconstruction can be largely improved. A case study is presented using a set of 2D SEM images with nanoscale pore structure from the low-density CSH (calcium silicate hydrate) phase of a hardened cement paste. Cross sections were randomly selected from the reconstructed 3D microstructure and compared with the original SEM images using the pore descriptors and the two-point correlation function with satisfactory agreement. Using the 3D reconstructed model, the properties of the sample material can be investigated on such a small scale as demonstrated in this paper on quantifying the absolute permeability.
提出了一种基于描述符的方法与一种分割方法相结合的方式，用于基于一组二维扫描电子显微镜（SEM）图像重建三维（3D）微观结构。利用分水岭算法识别SEM图像中的特征并将其分割成小特征。分水岭算法首先找到局部灰度最大值，并通过灰度局部最小值对特征进行分割。基于二维尺寸分布和径向分布，利用体视学分析分别推断小球形元素的三维尺寸分布和径向分布。通过基于模拟退火的过程匹配推断出的尺寸分布和径向分布来重建三维微观结构。结合所提出的分割方法，基于描述符的方法可应用于复杂微观结构，并且可以大大提高重建的计算效率。使用一组来自硬化水泥浆体低密度CSH（硅酸钙水合物）相的具有纳米级孔隙结构的二维SEM图像进行了案例研究。从重建的三维微观结构中随机选择横截面，并使用孔隙描述符和两点相关函数与原始SEM图像进行比较，结果吻合良好。利用三维重建模型，可以在如此小的尺度上研究样品材料的性质，如本文在量化绝对渗透率时所展示的那样。
