基于X射线断层扫描分析的发泡陶瓷结构

Structure of Foamed Ceramic Based on X-ray Tomography

根据发泡陶瓷形成的过程和结构特点,确定以扫描电子显微镜(scanning electron microscope,SEM)分析结构细节选取X射线断层扫描(X-ray computed tomography,X-CT)的体素,以泡孔形成及特征选取灰度阈值的方法.通过断层扫描图像、X-CT三维重构及可视化分析得到:发泡陶瓷由大孔和处于孔壁的小孔构成;发泡陶瓷泡孔基本处于连通状态,连通是由处于孔壁的小孔引起的;最大连通孔孔径不超过60μm,最小连通孔径在14μm左右;发泡陶瓷大孔的孔径处于0. 5~1. 0 mm,最大泡孔孔径值不超过2 mm,孔隙率为85. 97%;孔壁厚度集中在20~60μm.研究表明,X-CT在研究发泡陶瓷泡孔空间结构关系(即连通性)和泡沫材料大尺寸结构统计信息(孔径分布、壁厚分布等)方面具有明显优势.

According to the forming process and structural characteristics of foamed ceramics,the method of selecting voxels of X-ray computed tomography( X-CT) based on the structure details of scanning electron microscope( SEM) analysis and selecting gray threshold based on the formation and characteristics of pores was determined. Through tomographic images, X-CT three-dimensional reconstruction and visual analysis,the fact that the foamed ceramic consists of large pores and small pores on the pore wall was obtained. The foam ceramic pores are basically in a connected state,and the connection is caused by small holes in the cell wall. Furthermore,the maximum connected pore diameter is not more than 60 μm,and the minimum connected pore diameter is about 14 μm are demonstrated. It shows that the pore diameter of the foamed ceramic macropore is between 0. 5 and 1. 0 mm,the maximum pore diameter not more than 2 mm,and the porosity is 85. 97%. The thickness of the wall is concentrated between 20 and 60 μm. The research shows that X-CT has obvious advantages in studying the spatial structure relationship( i. e. connectivity) of foam ceramic pores and the statistical information( pore size distribution,wall thickness distribution,etc.) of large-size structure of foam materials.